President Obama rightly gets credit for authorizing a daring and successful ground raid into Pakistan to kill Osama bin Laden. But Obama is not a lone hero: it is instructive to trace the path U.S. policy took to get here over the last 25 years to demonstrate how presidents are always building on the groundwork laid by predecessors.

Covert action is authorized by a Presidential Finding. Findings are rare; more often, presidents sign Memoranda of Notification (MON) to further extend or modify an existing Finding. That is why to find the relevant finding behind the Abbottabad strike, we have to go all the way back to one signed in 1986 by President Ronald Reagan. The 1986 Finding describes the basic authorities for covert worldwide counterterrorism action by the military and intelligence community. The Finding was signed concurrently with the birth of the CIA's Counterterrorism Center (CTC), and finally started the slow gears of American bureaucracy churning against terrorists across the globe. Reagan was the first to make fighting terrorism official U.S. policy. (See Steve Coll's Ghost Wars).

President Bill Clinton signed a number of MONs further extending counterterrorism authorities, several specifically targeted at al-Qaida and Osama bin Laden, according to the 9/11 Commission Report and Ghost Wars. The military and intelligence community designed several operations to either kill or capture bin Laden several times in the late 90s. Clinton was the first to make fighting al-Qaida U.S. policy.

President George W. Bush dramatically expanded the counterterrorism authorities with an expansive MON signed shortly after 9/11 (detailed in Woodward's Bush At War). The authorities enabled intelligence operatives and special operations forces to embed with the Afghan Northern Alliance and overthrow the Taliban in 2001 (see Gary Schroen's First In and Gary Berntsen's Jawbreaker). They also eventually gave birth to the rumored drone program (here is a fascinating website that attempts to track the rumored done strikes). But the drones are relevant for Abbottabad not because of their missiles, but because of their cameras and sensors; they've helped build up years and years of data about militants which analysts have been able to mine for the smallest detail, crucial in the hunt for bin Laden.

Perhaps most directly relevant for the road to Abbottabad, Bush made a few key changes to the counterterrorism programs in 2008. Frustrated by years of stalemate, he expanded the authorized target list, began to approve missions without prior Pakistani approval, and also authorized ground incursions into Pakistan to pursue al-Qaida. (see Bob Woodward, Obama’s Wars, Chapter 1). Abbottabad was not the first widely-reported Navy SEAL incursion into Pakistan. Bush authorized a raid on the town of Angor Adda in September 2008 in pursuit of al-Qaida targets. The raid went poorly -- it was undertaken during Ramadan, when civilians were awake and feasting at night-Pakistani officials lashed out, and ground incursions were halted. But the precedent was set.

By the time Obama was faced with the compound in Abbottabad, he had the option of going in because of the large and sophisticated counterterrorism infrastructure and legal authorities built by his predecessors over a quarter-century. What Obama gets credit for is keeping these tools in place after he took office, and making full use of them. Unlike Clinton and his National Security Advisor, Sandy Berger, Obama actually authorized a strike against bin Laden when given the chance. And Obama was not deterred by the scandal of Angor Adda. That previous ground incursion proves that Obama took real risks when authorizing the Abbottabad strike. If Abbottabad had failed, it may have permanently ended the U.S.'s ability to go after terrorists inside Pakistan (as well as critically weakening the Obama presidency).

Presidents usually get more blame for the bad and more credit for the good that happens on their watch. Obama rightly deserves high praise for authorizing the Abbottabad mission. But Obama was right to give credit to the unnamed military and intelligence professionals whose tireless work over a decade made this victory possible. And I appreciated that Obama called President Clinton and, especially, President Bush to tell them the news on Sunday night. They share in this victory too.