Dockets of war.

• Author: Posner, Eric A.

Smart bombs cannot take out WikiLeaks. Stealth bombers cannot eliminate the bad odor wafting around Guantanamo Bay. Unmanned drones armed with Hellfire missiles cannot stop foreign countries and NGOs from putting America "on trial" for targeted killings. Lawfare is taking over international relations-or so many people believe. The most awesome military power in the world blunders about like a helpless giant in a dark room, swarmed by hostile forces that it cannot see and cannot attack.

First there's WikiLeaks' Julian Assange, who dealt U.S. diplomacy a serious blow when he posted thousands of cables disclosed to him by an American soldier named Bradley Manning. Yet the U.S. government is probably helpless to do anything about him. Justice Department officials investigating the possibility that Assange violated the Espionage Act worry that the law runs afoul of the First Amendment. Leakers like Manning can be prosecuted, but because few commit Manning's blunder of bragging about their exploits, they are rarely caught. If the government could prosecute disseminators, the epidemic of leaking could be mitigated. But that's a near impossibility.

And let us not forget Gitmo. The current administration drafted an executive order governing the detention of suspected members of al-Qaeda at Guantanamo Bay in the hopes of shutting down the facility by trying or releasing the detainees held there. This goal was shattered--on the rock of legal and political reality. Under the U.S. Constitution, evidence obtained by coercive interrogation cannot be used at trial. Thus, trials of at least some of the detainees would end in acquittals even though the U.S. government knows full well that those prisoners will restart their terrorism work as soon as they are freed. The Bush administration tried to avoid constitutional difficulties by relying on military commissions, but this strategy too failed. What America is left with is indefinite detention. And this is a political mess; according to some commentators, it is also constitutionally questionable.

In both cases, the legal constraint on national-security policies of the U.S. government is internal--it flows from the Constitution. But there are external legal constraints as well. Policy makers, including high-ranking military officials, have raised the alarm about the impact of international and foreign law on the American use of force. Many of America's allies (and many influential NGOS) support treaties that set significant limits on military action, often with vague phrasing that--in theory--leaves U.S. policy makers and soldiers vulnerable to prosecution by international courts and the national courts of foreign countries.

In 2001, Colonel Charles Dunlap (now major general, retired) of the U.S. Air Force famously described these legal constraints as "lawfare," which he defined as "the use of law as a weapon of war" and "the most recent feature of 21st century combat." (1) By this reading, lawfare is both the efforts of enemy nations, terrorist organizations and their supporters to counter American military superiority by threatening U.S. policy makers and soldiers with prosecution and civil litigation, and the pressure brought to bear by NGOs who take to the media marketplace insisting that international law places sharp limits on military action. In his 2007 memoir, former--Bush administration Justice Department official Jack Goldsmith disclosed that the risks posed by lawfare alarmed officials at the highest levels, including then-Secretary of Defense Donald Rumsfeld. (2)

The U.S. government has already undertaken defensive measures. Targeting decisions by the U.S. Air Force are subject to legal scrutiny before planes leave the ground; in fact, a lawyer can tell a commander that attacking a particular target is illegal because doing so risks excessive civilian casualties. The U.S. government has also expended significant diplomatic resources opposing treaties and international organizations that may ensnare American military operations. At this point, there is a palpable sense that lawfare may well end up compelling U.S. armed forces to curtail operations of significant strategic importance.

But the very idea of lawfare is perplexing. How can "law"--a set of rules applied by unarmed institutions like courts--stand up to bombs and missiles? The answer is that it cannot. Laws do not enforce themselves. If a weak country cannot coerce a more powerful country through force of arms, then it cannot coerce the other country with law either. The lawfare threat is greatly exaggerated.

The supposed external constraints are plentiful. Laws of armed conflict consist of a set of treaties (most famously, the Geneva Conventions) and customary norms that govern the use of force by the military, the most contentious of which is the requirement that civilian casualties not be "disproportionate" to the military...