For years now, President Obama and his party have been climbing out on a limb in Afghanistan which events are threatening to saw off.

Democrats from John Kerry on have argued that Afghanistan was the right battleground in the War on Terror; the place where George W. Bush took his eye off the ball to fight the war in Iraq. Obama picked up the theme and, as recently as last March, said this about Afghanistan: "We will use all elements of our national power to defeat Al Qaeda and to defend America, our allies and all who seek a better future."

Now we know that three weeks ago, the president was told by the general he sent to win the war that the need for tens of thousands more U.S. forces is so urgent that failure to send them could lead to defeat. Since then, the Afghan election has exposed how corrupt the U.S.-supported government is, making the fight against the Taliban insurgency all the more difficult.

Support for the war among Democrats in Congress is eroding and fast. The public is resisting as well, with the latest FOX poll showing a tiny plurality supporting the war, but a clear majority opposed to more troops.

Some on both the left and right see alarming parallels with Vietnam, another land of difficult terrain, corrupt government, hostile neighbors and border sanctuaries where the enemy can hide.

Soon, on this issue, there will be no place for the president to hide.

Brit Hume is the senior political analyst for FOX News Channel.