President Obama is giving a much-hyped counterterrorism address this afternoon at the National Defense University in which he'll announce new restrictions on drone strikes and targeted killings, and renew his push to shutter the Guantánamo Bay detention facility. But this isn't the Obama administration's first big speech on drone policy -- current and former officials, including Attorney General Eric Holder, former counterterrorism czar and current CIA chief John Brennan, former State Department legal adviser Harold Koh, and former Pentaon general counsel Jeh Johnson, have all delivered carefully crafted statements on the subject in recent years. Here's what we've learned so far.

The basics. Starting with the first major speech in March 2010 by Harold Koh, the Obama administration has sketched out a legal framework for drone strikes and other targeted killing operations -- though the fact that many of these strikes are conducted by remotely piloted vehicles wasn't acknowledged until a speech by John Brennan in May 2012. That justification rests on the 2001 Authorization for Use of Military Force against al Qaeda, which, in the administration's interpretation, allows for the use of force against al Qaeda-affiliated targets that pose an imminent threat to the United States in countries that have either given permission to the United States or are unwilling or unable to take action against the targets on their own. This rubric has been refined a bit -- but not much -- in subsequent speeches by Brennan and Eric Holder.

Yes, U.S. citizens can be targeted. There's legal precedent for the government using lethal force against American citizens abroad who have taken up arms against the United States, but the Obama administration did not lay out the rationale for such a scenario until a speech by Holder in March 2012. "The president may use force abroad against a senior operational leader of a foreign terrorist organization with which the United States is at war," Holder said in an address at Northwestern University, "even if that individual happens to be a U.S. citizen." Holder has since expanded on this in writing to indicate that the government does not have the authority to conduct targeted killings domestically. Additionally, in a letter to the Senate Judiciary Committee released on Wednesday, Holder revealed that targeted killings have killed four U.S. citizens since 2009, but that only one of them was the intended target of a strike.

Former officials would like to see more transparency -- to a point. Jeh Johnson has expressed concern about how limited public information about the drone program is affecting its reputation. "In the absence of an official picture of what our government is doing, and by what authority, many in the public fill the void by envisioning the worst," he said in a speech in March 2013. That sentiment was seconded by Koh; in a speech earlier this month, he told an audience at Oxford University that the administration "has not been sufficiently transparent to the media, to the Congress and to our allies." But Johnson wouldn't go so far as to endorse a court for approving targets, which he said could not provide the transparency and credibility its advocates suggest.

For every vague explanation that has been given in these drone speeches, though, there are more questions. Here are a few things we still don't know:

Who is the government really targeting? As Micah Zenko pointed out last month, internal government assessments obtained by McClatchy demonstrate that, in addition to members of al Qaeda, U.S. airstrikes have targeted hundreds of "Afghan, Pakistani and unknown extremists" from "the Haqqani network, several Pakistani Taliban factions and the unidentified individuals described only as 'foreign fighters' and 'other militants.'" That goes far beyond the limited scope that the Obama administration has outlined in a Justice Department white paper: that the United States can lawfully target a "senior operational leader of al-Qa'ida or an associated force" who "poses an imminent threat of violent attack against the United States." In his speech earlier this month, Koh stuck with what Zenko has called "the fundamental myth of the Obama administration's targeted killing program" -- that those targeted are clearly "cobelligerents" of al Qaeda. The administration has yet to discuss publicly the use of "signature strikes," in which groups are targeted based on a set of observed behaviors that are similar to those of terrorist cells.

Just how imminent is 'imminent'? What determines when capture isn't 'feasible'? That Justice Department white paper has a lot of fuzzy language in it. Targeted killings are authorized by "an informed, high-level official of the US government" when there is an "imminent threat of violent attack" and capture is deemed "unfeasible." But really, who qualifies to make that call? Does simply being a member of al Qaeda make someone an imminent threat, or does there have to be a specific plot associated with the individual or cell? Capture was feasible for Osama bin Laden in a safehouse just outside a military base in the heart of Pakistan, but not for men riding in an SUV bumping along a rural Yemeni road -- who makes that determination, and how? Rosa Brooks has written more about how the white paper said a lot by not saying very much at all.

Where and when does the 2001 Authorization for Use of Military Force not apply? In his February 2012 speech, Johnson called the AUMF "the bedrock of the military's domestic legal authority" for drone strikes and the broader war on terror -- but the AUMF was written to target individuals responsible for the attacks of Sept. 11, 2001. It's been a bit of a stretch for the administration to claim that this authorizes them to target organizations only tangentially affiliated with al Qaeda -- some of which didn't even exist in 2001, and some analysts and politicians have argued that it's time to revise the AUMF. Or, as Brooks has asserted, it might make more sense to scrap it altogether and start over with a new law that doesn't try to shoehorn new authorizations into an old law with more legalese.

But if past speeches are any indication, don't expect too many answers today.

On Tuesday, a landmark immigration bill that would put 11 million undocumented immigrants on the path to U.S. citizenship cleared the Senate Judiciary Committee, but not before Sen. Lindsey Graham (R-SC) added an amendment requiring additional screening for immigrants hailing from an unspecified number of countries that pose a heightened terrorist threat. As Hayes Brown reports over at ThinkProgress, the Graham amendment mandates additional review for those who are from "a region or country known to pose a threat, or that contains groups or organizations that pose a threat, to the national security of the United States."

"[I]t's pretty clear what I'm trying to do," Graham said during a markup of the bill. "I'm trying to make sure that in addition to looking at your criminal background, when you adjust status, that if there are certain parts of the world or countries -- like Yemen -- that you're adjusting from, I want to know a little more about you, given the world we live in."

The Graham amendment declines to name specifically which countries would trigger the additional screening, but leaves the determination up to the secretary of homeland security in consultation with the secretary of state.

When reached for comment, Graham's office reiterated that the decision would rest with the Department of Homeland Security but confirmed that the State Department's Foreign Terrorist Organizations list could conceivably serve as a guide. "The DHS Secretary can simply use the list maintained by State but is free to go beyond it," a spokesman for Graham told FP in an email.

If the State Department list were to ultimately serve as the guide, however, Graham's amendment might apply to an exceptionally broad class of applicants. The list, which identifies foreign terrorist groups that threaten "the security of United States nationals or the national security of the United States," catalogues 52 organizations operating in dozens of countries, including many not ordinarily associated with terrorism.

The irony of the Graham amendment is that it's been billed by critics as an attempt to resurrect the post-9/11 National Security Entry-Exit Registration System (NSEERS), which forced immigrants from 24 Muslim countries to undergo additional scrutiny until it was mostly abandoned by the Obama administration in 2011. But by targeting immigrants from states that "contain groups or organizations" that threaten the United States -- assuming the State Department list is used to make such determinations -- Graham's amendment would go far beyond the NSEERS, applying to immigrants from dozens of countries on virtually every continent.

Far from only applying to Muslim or Middle Eastern countries, the amendment would apply, for example, to immigrants from Greece, Ireland, and Spain, all of which have terrorist organizations that appear on the State Department's list operating within their borders. It would also apply to immigrants from India, Thailand, Singapore, Malaysia, Bangladesh, the Philippines, and Indonesia, to name just a few. Countries "where terrorists operate," as Graham put it during the markup, actually make up a sizable chunk of the planet.

Graham's amendment, which passed by voice vote and was inserted into the bill, will most likely face opposition from Democrats when it's debated on the Senate floor next month. Whether or not they take issue with its extraordinary breadth remains to be seen.  

Ahead of President Obama's big counterterrorism speech tomorrow, Attorney General Eric Holder has written a letter, obtained by the New York Times, to the Senate Judiciary Committee disclosing the four American citizens killed by targeted strikes during the Obama administration, three of whom "were not specifically targeted by the United States":

Since 2009, the United States, in the conduct of U.S. counterterrorism operations against al-Qa'ida and its associated forces outside of areas of active hostilities, has specifically targeted and killed one U.S. citizen, Anwar al-Aulaqi. The United States is further aware of three other U.S. citizens who have been killed in such U.S. counterterrorism operations over that same time period: Samir Khan, 'Abd al-Rahman Anwar al-Aulaqi, and Jude Kenan Mohammed. These individuals were not specifically targeted by the United States.

The letter does not include the names of all Americans who have been killed in drone strikes. A fifth U.S. citizen, Ahmed Hijazi (a.k.a. Kamal Derwish) was killed in 2002 during the Bush administration in the first ever U.S. drone strike. That strike, in Yemen, was directed at Qaed Salim Sinan al-Harethi, who was associated with the bombing of the USS Cole in 2000. An unnamed FBI source told the Seattle Post-Intelligencer several years ago that another U.S. citizen was believed to have been killed by a U.S. cruise missile in Somalia sometime between 2006 and early 2009.

Anwar al-Awlaki and Samir Khan were propagandists for al Qaeda in the Arabian Peninsula (AQAP), and the U.S. government believes that Awlaki played a role in planning the attempted underwear bombing in 2009. His son, 'Abd al-Rahman, had reportedly linked up with AQAP members while looking for Awklaki when a drone targeted his vehicle. The three men were killed in a series of airstrikes in September and October 2011.

The only new name is Jude Kenan Mohammed, whose death in Pakistan was rumored in a February 2012 local news story in his hometown of Raleigh, N.C but had not been previously acknowledged.

With the letter, the Obama administration has now admitted killing more U.S. citizens than detainees the Bush administration admitted waterboarding. Hooray for transparency?

The full text of Holder's letter is included below:

Two assailants reportedly killed a man near a military barracks in south London on Wednesday, in a shocking attack that is dominating British press coverage right now. The exact details of what transpired in the Woolwich district are hazy, but here's what we know so far: Early witness reports describe a brutal assault in which two attackers ran over a man who may have been a soldier, attempted to behead him, and then stuck around to have their photo taken by passersby. When police arrived on the scene, the men brandished their weapons -- which may have included a handgun, a machete, and knives -- at law-enforcement officials, and both were shot, subsequently arrested, and taken to the hospital.

ITV, a British television station, obtained footage of what appears to be one of the attackers explaining his motivations. In the unconfirmed video, filmed by a bystander who had been traveling by bus to a job interview, a man with bloodied hands carrying a kitchen knife and a meat cleaver says the attack was in retribution for Muslim deaths:

We swear by almighty Allah we will never stop fighting you until you leave us alone. Your people will never be safe. The only reasons we have done this is because Muslims are dying by British soldiers every day. This British soldier is an eye for an eye, a tooth for a tooth.

In the clip, you can hear him add:

I apologize that women had to witness this today but in our lands our women have to see the same. You people will never be safe. Remove your government. They don't care about you.

The video, which also shows the two attackers shortly after they are shot by police, is below (warning: it's graphic).

A witness who only gave his first name, James, described a horrific scene. "These two guys were crazed. They were just animals. They dragged him from the pavement and dumped his body in the middle of the road and left his body there," he told LBC radio.

Nick Raynsford, the member of parliament who represents Woolwich, has described the victim as a soldier, but so far there has not been an official confirmation of the man's identity. British Prime Minister David Cameron, in Paris for a meeting with French President François Hollande, has said there are "strong indications that this is a terrorist incident."

The attack is drawing a chorus of condemnations. London Mayor Boris Johnson had this to say on Twitter: 

This afternoon's attack in Woolwich is a sickening deluded and unforgivable act of violence. My thoughts are with the victim and his family

— Boris Johnson (@MayorofLondon) May 22, 2013

The Muslim Council of Britain, responding to the invocation of Allah made by the alleged attacker seen in the ITV video, has also condemned the attack:

This is a truly barbaric act that has no basis in Islam and we condemn this unreservedly. Our thoughts are with the victim and his family. We understand the victim is a serving member of the Armed Forces. Muslims have long served in this country’s Armed Forces, proudly and with honour. This attack on a member of the Armed Forces is dishonourable, and no cause justifies this murder.

We'll update as we learn more.

Update, 12:35 p.m. 5/22/13: The soldier killed in Wednesday's attack has been identified by the British Ministry of Defense as Drummer Lee Rigby, 25, of the 2nd Battalion of the Royal Regiment of Fusiliers. A native of Crumpsall, Manchester, Rigby served as a drummer during the regiment's ceremonial duties and deployed to Helmand province in Afghanistan in April 2009. Described as a charismatic, humorous man, Rigby -- or "Riggers" as he was known to his friends -- had taken up a recruiting job at his London base.

"Riggers is what every battalion needs. He was one of the Battalion's great characters always smiling and always ready to brighten the mood with his fellow Fusiliers," said Ned Miller, a warrant officer first class and regimental sergeant major of the second fusiliers. "He was an excellent drummer and well respected within the Drums platoon. He was easily identified whilst on parade by the huge smile on his face and how proud he was to be a member of the Drums. He would always stop for a chat just to tell me Manchester United would win the league again."

Rigby is survived by his two-year-old son, Jack.

You've read the stories about Sweden's excellent health care system, innovative gender-neutral day care centers, and generous parental leave policies. But here's a story that those who would like to portray Sweden as a socialist paradise are less eager to tell: For three consecutive nights, the residents of several largely immigrant suburbs have rioted, torching cars, clashing with police, and setting buildings ablaze.

The rioting -- the worst social unrest to strike the country in many years -- was sparked by the lethal police shooting of a 69-year-old, knife-wielding man last week in the suburb of Husby, the epicenter of the riots. Roaming gangs of angry youths have since clashed with police and Husby residents have complained of racist treatment by police officers, who they say have used epithets such as "monkey."

What's happening in Husby is clearly a symptom of Sweden's failed effort to integrate its massive immigrant population. Housing segregation is rampant in the country, and Husby is a case study in how immigrant populations have come to dominate Stockholm's outer suburbs. The graph below (from this paper on housing segregation) illustrates the phenomenon. Depending on your political perspective, native-born Swedes have either fled Husby or been pushed out by immigrants:

Husby also suffers from rampant unemployment -- a problem that is particularly acute for its youth. Nearly 30 percent of the city's young people are neither employed nor actively enrolled in school, a number that mirrors a broader trend of immigrant underemployment relative to the native-born population.

The riots have been captured in YouTube videos, which paint a picture of an aggressive, somewhat ham-handed response by police. When confronted by angry residents, law enforcement officials have used dogs and drawn pistols to intimidate the crowds. In the clip below, they can be seen charging residents -- then retreating and charging once more.

Police have also used dogs to disperse the crowds. Here, the officer tells a resident to back up or risk being bitten. The female voice at the end of the video repeatedly asks police, "Aren't you ashamed of yourselves?!"

Here's what things looked like from one of the apartment buildings in the area. As you can see in the video, Husby has massive housing structures, part of the so-called Million Program to vastly expand the country's residential properties.

And here's a panicked Swedish reporter covering a car fire in Husby. He excitedly relates how a piece of metal came flying at "high speed" toward the "exact spot" where he had been filming. When he tries to pick it up to show the camera, he declares it far too hot. The headline on the video translates as "Expressen's reporter forced to seek cover."

The reaction of Sweden's political class to the riots has been mixed. The nativist Sweden Democrats have called on the police to deploy water cannons to disperse the rioters. Meanwhile, the head of the largest opposition party, the Social Democrats, made a covert nighttime visit to Husby to talk to residents. Prime Minister Fredrik Reinfeldt has said neither he nor any members of his government are likely to pay a visit to the suburb, and declared that "Sweden cannot be ruled by violence" (his critics might point out that police violence sparked the rioting).

In short, no one has any real idea what to do about the unrest in the country -- besides praying that Molotov cocktails don't reappear on the streets of Husby tonight.

Russia's Green Alliance - People's Party, which registered as a political party just one year ago, has turned to art to take a stab at the country's ruling United Russia party.

Taking advantage of a contest to design an emblem for the greater Moscow region, the Green Alliance has submitted an entry to the local ministry of culture that takes multiple swipes at United Russia -- highlighting problems with the country's leaders and many of the social issues that the ruling party has failed to address.

The Green Alliance has made no secret about the meaning of the design. On Tuesday, the party even tweeted a key to all the symbols packed into the image:

???? ??????? ?????????? ? ???????????? ???????? ?????????? ??????? ?????? ?? ??????? "?????? ???????????" twitter.com/RussianGreens/...

— ?????? ??????? (@RussianGreens) May 21, 2013

Here's our own (English-language) guide:

The bear is a nod to the symbol of United Russia, but in this image the animal looks sinister and thuggish.

The gold chain the bear is wearing represents United Russia's alleged ties to the mob. 

The saw and tree stumps symbolize United Russia's disregard for nature. As the Moscow Times points out, it was the previous United Russia governor who launched construction of the Moscow-St. Petersburg highway through the Khimki forest.

The cracked road draws attention to the Moscow region's poor infrastructure, which, the Green Alliance claims, is typically only "repaired by kickbacks."

The blue flashing light, which many Moscow drivers use to abuse traffic laws, is a symbol of "the power of contemporary feudalists," according to the party.

The high-rises in the background are meant to be "new buildings, without social infrastructure, built next to dumps."

The two men holding up the central shield are illegal migrant workers from central Asia. The Green Alliance points out that there are an estimated three million illegal migrants living in the Moscow region. 

The "garlands" of paper money surrounding the shield represent the "harvest collected by [corrupt] bureaucrats."

"At a time when an alternative point of view doesn't appear in regional mass media, we consider it our duty to use this emblem as a way of drawing attention to problems," the Green Alliance's leader told the Moscow Times. It's a noble objective. But don't expect local officials to stamp the image on Moscow's promotional materials anytime soon.

Christian Caryl contributed to this post.