War has changed. The laws of war must, too.

One of the most striking developments of the post-cold war era has been the shift in our understanding of war itself. This most ancient of human behaviors has literally taken on a new definition. The 1985 edition of Webster's Ninth New Collegiate Dictionary described war as "a state of usu. open and declared armed hostile conflict between states or nations."

How shopworn that formulation seems today. Warfare in the 21st century is increasingly the domain of non-state actors – of tribes, cells, clans, and networks. As the nature of war undergoes significant change, so, too, must the laws of war.

Of course, the very notion that warfare – an activity that necessarily entails premeditated homicide and the intentional destruction of property – could be channeled or civilized by statute has always been a bit problematic. Yet there is a long and distinguished history of such legislation, and it has made a difference.

These laws, which include the Geneva Conventions, the Hague Regulations, and other treaties, have been developed and refined over the centuries to reflect changes in warfare and humanitarian standards. Six hundred years ago, few would have objected to King Henry V's order, immortalized by William Shakespeare, that "every soldier kill his prisoners." But today, that directive would be justifiably disobeyed and universally condemned, because slaughtering prisoners is a recognized war crime.

The last major revision to the laws of war took place in Geneva in 1949, more than a half-century ago. Today, the world needs new rules of war that reflect a world in which "combatants" may wear jeans and sweatshirts instead of uniforms with distinctive insignia. The United States, as the world's superpower and greatest military force, should lead the charge to revise the laws of war to address today's threats.

The Geneva protocols offer little guidance for the definition or treatment of terrorists. Beginning with the Military Commissions order in 2001, the Bush administration has attempted to fill the gaps in international law by developing rules for the treatment, detention, and prosecution of "enemy combatants" belonging to Al Qaeda and the Taliban. The purpose was to distinguish these combatants from traditional soldiers, and deny them prisoner-of-war (POW) status.

The Geneva Conventions grant POW status to those who abide by the laws of war, operate pursuant to a chain of command, wear distinctive insignia, and carry arms openly. By contrast, terrorists gain their lethal advantage precisely by blending into the populace, concealing their weapons, and blurring their chain of command – if such a chain even exists in the first place.

POW status is important for those captured on the battlefield, because it confers many benefits and protections – including guarantees of humane treatment, medical care, physical exercise, advances of pay, and freedom to practice one's religion.

Geneva's provisions state that POWs are obligated only to inform their captors of their name, rank, serial number, and date of birth, and that "[N]o physical or mental torture, nor any other form of coercion, may be inflicted on prisoners of war to secure from them information of any kind whatever." In addition, POWs must be released "without delay after the cessation of active hostilities."

Such rules for the treatment of POWs present some obvious problems when dealing with suspected terrorists. In order to unearth future terrorist actions, governments need to learn a bit more from these prisoners than name and birthdate.

Then there is the question of how the current protocols apply to a "war" that may never end. Because terrorists present a continuing threat, nations must be allowed to detain those who are reasonably suspected of enacting or abetting such plots. However, baseline standards for detention must be established, including periodic reviews of each suspect's case.

Congress attempted to address these issues by passing the Military Commissions Act of 2006. This law, signed by President Bush last month, attempts to define unlawful enemy combatants and describe standards for detention and treatment.

This unilateral approach to revising international law is misguided, because it may set a precedent for other nations to reinterpret the Geneva Conventions in their own interests to the detriment of US troops. In addition, some of its more dubious provisions – including denial of habeas corpus rights – have already prompted significant domestic and international criticism. The law may not even survive constitutional scrutiny by the Supreme Court.

It is time for a more effective approach to redefining the Geneva accords. If America hopes to persuade other nations of the legitimacy of its counterterrorism campaigns, it must work to rebuild its moral authority by helping to create internationally accepted standards. An American call for a full modernization of the Geneva Conventions – one that would create multilateral standards for the treatment, detention, and prosecution of enemy combatants – might be a good place to start.

Scott Holcomb is an Atlanta attorney who served as a legal adviser to Army generals during the wars in Afghanistan and Iraq from 2001-2003. Mark Ribbing is a St. Louis-based freelance writer who wrote speeches for former New York Mayor Rudolph Giuliani.