Our enemy now is a stateless network of religious extremists. They do not obey the laws of war, they hide among peaceful populations and launch surprise attacks on civilians. They have no armed forces per se, no territory or citizens to defend and no fear of dying during their attacks.

The United States has used force abroad more than 130 times, but has only declared war five times - the War of 1812, the Mexican-American War, the Spanish-American War, and World Wars I and II.

Al Qaeda operates by launching surprise attacks on civilian targets with the goal of massive casualties. Our only means for preventing future attacks, which could use WMDs, is by acquiring information that allows for pre-emptive action.

An American leader would be derelict of duty if he did not seek to understand all his options in such unprecedented circumstances. Presidents Lincoln during the Civil War and Roosevelt in the lead-up to World War II sought legal advice about the outer bounds of their power - even if they did not always use it. Our leaders should ask legal questions first, before setting policy or making decisions in a fog of uncertainty.

While Taliban fighters had an initial claim to protection under the conventions, they lost POW status by failing to obey the standards of conduct for legal combatants: wearing uniforms, a responsible command structure, and obeying the laws of war.

I do not think that torture is necessary. But it may be the case that interrogation methods that go beyond questioning, but do not arise to the level of torture, may be necessary to get actionable intelligence from high-ranking al Qaeda leaders.

Declarations of war have never been a constitutional requirement for military action abroad. The United States has used force abroad more than 130 times, but has only declared war five times - the War of 1812, the Mexican-American War, the Spanish-American War, and World Wars I and II.