I believe that the power to declare war is most important in limiting the powers of the national government in regard to the rights of its citizens, but that it does not require Congress to give its approval before the president uses force abroad.

I think it can be very important for the president to seek congressional approval for war , even though not constitutionally required to do so, in certain situations. It makes sense to go to Congress to signal our national resolve and our willingness to fight to defend other nations or the freedom of their peoples.

Declarations of war have never been a constitutional requirement for military action abroad.

Human rights advocates, for example, claim that the mistreatment of Iraqi prisoners is of a piece with President Bush's 2002 decision to deny al Qaeda and Taliban fighters the legal status of POWs under the Geneva Conventions.

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.

The United States is at war with the al Qaeda terrorist group. Al Qaeda is not a nation-state and it has not signed the Geneva Conventions. It shows no desire to obey the laws of war; if anything it directly violates them by disguising themselves as civilians and attacking purely civilian targets to cause massive casualties.

It is easy now for critics to claim that the work was poor; they haven't produced their own analyses or confronted any of the hard questions. For example, would they say that no technique beyond shouted questions could be used to interrogate a high-level terrorist leader, such as Osama bin Laden, who knows of planned attacks on the United States?