This budget bill — which can be vetoed without cutting financing for our troops — is both misguided and unnecessary: the president already has the power and flexibility to effectively fight terrorism.

One provision would authorize the military to indefinitely detain without charge people suspected of involvement with terrorism, including United States citizens apprehended on American soil. Due process would be a thing of the past. Some claim that this provision would merely codify existing practice. Current law empowers the military to detain people caught on the battlefield, but this provision would expand the battlefield to include the United States — and hand Osama bin Laden an unearned victory long after his well-earned demise.

A second provision would mandate military custody for most terrorism suspects. It would force on the military responsibilities it hasn’t sought. This would violate not only the spirit of the post-Reconstruction act limiting the use of the armed forces for domestic law enforcement but also our trust with service members, who enlist believing that they will never be asked to turn their weapons on fellow Americans. It would sideline the work of the F.B.I. and local law enforcement agencies in domestic counterterrorism. These agencies have collected invaluable intelligence because the criminal justice system — unlike indefinite military detention — gives suspects incentives to cooperate.

Mandatory military custody would reduce, if not eliminate, the role of federal courts in terrorism cases. Since 9/11, the shaky, untested military commissions have convicted only six people on terror-related charges, compared with more than 400 in the civilian courts.

A third provision would further extend a ban on transfers from Guantánamo, ensuring that this morally and financially expensive symbol of detainee abuse will remain open well into the future. Not only would this bolster Al Qaeda’s recruiting efforts, it also would make it nearly impossible to transfer 88 men (of the 171 held there) who have been cleared for release. We should be moving to shut Guantánamo, not extend it.

Having served various administrations, we know that politicians of both parties love this country and want to keep it safe. But right now some in Congress are all too willing to undermine our ideals in the name of fighting terrorism. They should remember that American ideals are assets, not liabilities.

Charles C. Krulak and Joseph P. Hoar are retired four-star Marine generals.