When the Senate resumes debate on the 2012 defense authorization bill this week, one of the many issues we will turn to is the best way to handle the detention of suspected terrorists.

The United States has struggled to craft laws and procedures to prosecute the unprecedented kind of war that came to our shores on Sept. 11, 2001. The courts, Congress and two presidential administrations have gradually, often ad hoc, developed a system that seeks to uphold our values and honors our Constitution while protecting national security. Congress — in particular, the Senate Armed Services Committee — has worked hard to establish in law this important balance rather than rely solely on court orders and executive orders that can change with administrations.

The bill, which was unanimously approved by the committee, builds on that work. Its provisions on detainees represent a careful, bipartisan effort to provide the executive branch the clear authority, tools and flexibility of action it needs to defend us against the threat posed by al-Qaeda.

We are concerned that much of the debate over these provisions demonstrates a basic misunderstanding of what this bill would do and attributes to it many things that it would not do.

The most controversial point involves the circumstances under which a terrorist detainee should be held in military, rather than civilian, custody. The bill provides that a narrowly defined group of people — al-Qaeda terrorists who participate in planning or conducting attacks against us — be held in military custody.

However, the bill does allow the administration, through a waiver, to hold these al-Qaeda detainees in civilian custody if it determines that would best serve national security. Moreover, the administration has broad authority to decide who is covered by this provision and how and when such a decision is made.

Just as important as what the bill does is what it does not do. Contrary to the claims of some critics:

●No provision in the legislation expands the authority under which detainees can be held in military custody. On the contrary, it codifies detention authority that has been adopted by two administrations and upheld in the courts. The bill states clearly that it does not expand or limit the president’s authorities under the original 2001 authorization of the use of force against al-Qaeda.

●The bill does not tie the administration’s hands in deciding how best to handle a detainee. It is the executive branch that determines whether a detainee meets the criteria for military custody, under procedures that this legislation allows the executive branch to develop. Not only does the bill include a national security waiver, but it expressly authorizes the transfer of any military detainee to civilian custody for trial in the federal courts.

●The bill does not threaten to interrupt ongoing surveillance operations or interrogations or damage time-sensitive anti-terrorism operations. In fact, it specifically prohibits the interruption of ongoing surveillance, intelligence-gathering or interrogation sessions.

●The bill does not create new restrictions on the transfer of detainees from Guantanamo, either to foreign countries or to the United States. It does maintain some existing limits but gives the administration greater flexibility in waiving them. The bill doesn’t prohibit the transfer of detainees to the United States, and the limits it imposes on transfers to third countries are less restrictive than is past legislation by making the certification requirements for such transfers easier to use.

Congress has passed a defense authorization bill every year for five decades. This year’s bill includes pay raises for our troops, funding for equipment to protect them from roadside bombs, and medical care and other benefits for them and their families. It would be extremely unfortunate if disagreements over these detainee provisions prevented us from passing this bill and fulfilling those duties. But it would be tragic if this happened because of misunderstandings about what the bill says and does.

We hope our colleagues, President Obama and his advisers will recognize the substantial work we have done to accommodate their concerns and work with us to pass a bill that honors our values and protects our nation.

Carl Levin, a Democrat from Michigan, and John McCain, a Republican from Arizona, are, respectively, the chairman and ranking minority member, respectively, of the Senate Armed Services Committee.