Al-Qaeda and Hamas. Legal justifications for targeted killing The U.S. Army's Law of Land Warfare (Field Manual 27–10) states: 31. Assassination and Outlawry It is especially forbidden * * * to kill or wound treacherously individuals belonging to the hostile nation or army. [Article 23(b) of the 1907 Hague Regulations] This article is construed as prohibiting assassination, proscription, or outlawry of an enemy, or putting a price upon an enemy's head, as well as offering a reward for an enemy "dead or alive". It does not, however, preclude attacks on individual soldiers or officers of the enemy whether in the zone of hostilities, occupied territory, or elsewhere. Daniel Reisner, who headed the International Legal Division of the Israeli Military Advocate General's Office from 1994 to 2005, has stated that although targeted killing is illegal under previous understanding of international law, "If you do something for long enough, the world will accept it. The whole of international law is now based on the notion that an act that is forbidden today becomes permissible if executed by enough countries." Reisner continues, "International law progresses through violations. We invented the targeted assassination thesis and we had to push it. At first there were protrusions that made it hard to insert easily into the legal moulds. Eight years later it is in the center of the bounds of legitimacy." This view is disputed by George Bisharat of the University of California's Hastings College of the Law, who contends that assassination is not widely regarded as legal. Georgetown Law Professor and former U.S. Marine, Gary Solis, has argued that under certain conditions, "Assassinations and targeted killings are very different acts." For Solis, these conditions require that there is an ongoing military conflict, the targeted individual (civilian or military) has taken up arms, that there is no reasonable possibility of arrest, and that the decision to kill is made by senior political leaders. Abraham Sofaer, a former legal advisor to the U.S. State Department and fellow at the conservative Hoover Institution think tank, has written that targeted killing is "sometimes necessary, because leaders are obliged to defend their citizens". After the killing of Hamas founder and quadriplegic Ahmed Yassin by Israeli helicopter gunships, Sofaer argued that targeted killing is not prohibited by American Executive Order 11905 banning assassination: "killings in self-defense are no more 'assassinations' in international affairs than they are murders when undertaken by our