If you were one of the Americans waiting for Congress, under Democratic control, to show leadership on the war in Iraq, the message from the Senate is clear: “Nevermind.” The same goes for those waiting for lawmakers to fix the damage done to civil liberties by six years of President Bush and a rubber-stamp Republican Congress.

The Democrats don’t have, or can’t summon, the political strength to make sure Congress does what it is supposed to do: debate profound issues like these and take a stand. The Republicans are simply not interested in a serious discussion and certainly not a vote on anything beyond Mr. Bush’s increasingly narrow agenda.

On Wednesday, the Senate failed to vote on two major bills. One would have restored basic human rights and constitutional protections to hundreds of foreigners who are in perpetual detention, without charges or trial. The other was the one measure on the conduct of the Iraq war that survived the Democrats’ hasty retreat after last week’s smoke-and-mirrors display by Gen. David Petraeus and President Bush.

There were votes, of course, but not on the bills. They were cloture votes, which require 60 or more Senators to agree to cut off debate, eliminating the possibility of a filibuster, so Senators can vote on the actual law. In both cases, Democrats were four votes short, with six Republicans daring to defy the White House.

We support the filibuster as the only way to ensure a minority in the Senate can be heard. When the cloture votes failed this week, the Democrats should have let the Republicans filibuster. Democratic leaders think that’s too risky, since Congress could look like it’s not doing anything. But it’s not doing a lot now.

The country needs a lot more debate about what must be done to contain Iraq’s chaos and restore civil liberties sacrificed to Mr. Bush’s declared war on terrorism. Voters are capable of deciding whether Republicans are holding up the Senate out of principle or political tactics.

The current Republican leadership, now in the minority, has organized its entire agenda around the filibuster. In July, the McClatchy newspaper group reported that Republicans were using the threat of filibuster more than at any other time in the nation’s history.

Remember, this is the same batch of Republican senators who denounced Democrats as obstructionist and even un-American and threatened to change the Senate’s rules when Democrats threatened filibusters in 2005 over a few badly chosen judicial nominees. Now Republicans are using it to prevent consideration of an entire war.

If anything was clear from General Petraeus’s testimony and the president’s prime-time speech, it was that Mr. Bush has no idea how to end the war in a way that salvages as much as possible of America’s treasury, blood and global image while limiting the chaos that would follow any withdrawal, whether it comes quickly or slowly. Mr. Bush’s only idea is to keep the war going until he leaves office, and that means that other co-equal branch of government, the Congress, will have to lead the way out.

Democrats and Republicans who oppose the war have a duty to outline alternatives. Those who call for staying in Iraq have a duty to explain what victory means and how they plan to achieve it. Both sides are shirking an obligation to deal with issues that must be resolved right now, like the crisis involving asylum for Iraqis who helped the American occupation.

Congress is the first place for this kind of work. Right now, it seems like the last place it will happen.