The nighttime attack on Osama bin Laden’s compound by the elite Joint Special Operations Command isn’t the first time U.S. troops have entered Pakistan for covert raids. In the past, such incidents have drawn protests from the Pakistani government, though it has a history of condemning in public actions that it has endorsed in private.

Details on the latest mission are of course very sketchy, and we thought it would be helpful to run through what’s known about previous raids—and just how much remains unknown even years later. Details have been particularly difficult to pin down given frequent denials by U.S. and Pakistani officials.

In 2005, a secret operation by Navy Seals to capture al-Qaida members in Pakistan was aborted because Bush administration officials felt it was too risky and could jeopardize U.S. ties with Pakistan, the New York Times reported in 2007.

Both the New York Times and Los Angeles Times had reported that in 2006, a Navy Seal team raided a militant compound in Pakistan. That year, the Washington Post published a piece on the hunt for Osama bin Laden, quoting U.S. officials saying that the Joint Special Operations Command had been given the authority to enter Pakistan under certain circumstances—with the understanding that the Pakistan government will deny having granted permission. (The National Journal has more on JSOC and the special ops team that carried out the Osama mission.)

In September 2008, the U.S. conducted a ground raid in Pakistan by helicopter-borne special forces. It seems to have been the first publicly acknowledged U.S. ground raid in Pakistan and was decried by Pakistani officials, who called the attack a “gross violation of Pakistan’s territory” and threatened retaliatory action.

Then in 2009, the UK’s Guardian newspaper quoted a NATO official stating that the scope of the raids was beyond what has been reported, extending as far back as 2003:

A former Nato officer said the incursions, only one of which has been previously reported, occurred between 2003 and 2008, involved helicopter-borne elite soldiers stealing across the border at night, and were never declared to the Pakistani government.

"The Pakistanis were kept entirely in the dark about it. It was one of those things we wouldn't confirm officially with them," said the source, who had detailed knowledge of the operations.

Asked about the reports, State Department spokesman P.J. Crowley said in December 2009, “I’ll defer to my colleagues at the Pentagon, but I would question the validity of those reports.”

The United States also denied a report last year in the New York Times that said that senior military officials were pushing a plan to expand special forces ground raids in Pakistan. These denials came as the Washington Post reported last year that the Obama administration has expanded the scope of the Special Operations forces, growing their presence to more than 74 countries in 2010.

White House Press Secretary Robert Gibbs, asked about the plan for more raids in Pakistan, would only quote NATO’s statement, which denied the report:

I think the best thing to do is to quote ISAF. And let me read their release from last night, if I can find it in my stack. “There’s absolutely no truth to the reporting in The New York Times that U.S. forces are planning to conduct ground operations into Pakistan. ISAF and U.S. forces, along with their Afghan partners, have developed a strong working relationship with the Pakistan military to address shared security issues. The coordination recognizes the sovereignty of Afghanistan and Pakistan to pursue insurgents and terrorists operating in their respective border areas.”

Despite this supposed “strong working relationship,” the Obama administration has been upfront about the unilateral nature of its latest strike.

“We shared our intelligence on this bin Laden compound with no other country, including Pakistan,” a senior administration official told reporters. “That was for one reason and one reason alone: We believed it was essential to the security of the operation and our personnel.”

Pakistani leaders were informed shortly after the raid, and they not only haven’t had their usual response of fury and condemnation, they seem to have barely responded at all. The Pakistani foreign ministry issued a statement confirming the death. Reuters notes that Pakistan’s president, prime minister, military spokesmen and spy agency have not said anything publicly about the raid.

WikiLeaks cables also show that in recent years the Pakistani Army quietly approved the deployment of U.S. special forces to provide support to Pakistani military operations. “These deployments are highly politically sensitive because of widely-held concerns among the public about Pakistani sovereignty and opposition to allowing foreign military forces to operate in any fashion on Pakistani soil,” the October 2009 cable noted.

Another cable, from February 2009, described a U.S.-Pakistan relationship based on “mutual mistrust.” “Pakistan hedges its bets on cooperation because it fears the U.S. will again desert Islamabad after we get Osama bin Laden,” the cable read. “The relationship is one of co-dependency we grudgingly admit—Pakistan knows the U.S. cannot afford to walk away; the U.S. knows Pakistan cannot survive without our support.”