WASHINGTON — This is how it ends. The long debate over the Iraq war that consumed so much of the new Democratic-run Congress this year, especially in the Senate where Nevada’s Harry Reid is the majority leader, headed tonight toward its quiet conclusion.

Fifty senators voted at about 8:30 p.m. EST for a non-binding “sense of the Senate” resolution that says the military mission in Iraq should be transitioned to a more limited one, with the “goal” of completing that transition by the end of 2008.

It was the same sort of transition President Bush had called for in September — using the military for counter-terrorism and to train the Iraqi Army. But before the vote, the Republican leader, Sen. Mitch McConnell of Kentucky, reminded senators that Bush would reject their big, year-end spending package if they attached this amendment to the bill.

The resolution fell short of the 60 it needed to pass, even with some Republican support.

Instead, the Senate went on to approve McConnell’s amendment, 70-25, which gives Bush $70 billion to keep fighting the wars in Iraq and Afghanistan for several more months, as the president wanted.

The Senate is almost done for the night, and the year, and another day is beginning in Iraq.