President Obama is trying to decide whether to commit additional troops to Afghanistan to stabilize the country, repulse a resurgent Taliban and continue the fight against al-Qaida.

If you're looking for a clue as to which way the president might be leaning, consider this: The Washington Post reported Tuesday that the Pentagon is deploying an additional 13,000 troops to Afghanistan, above and beyond the 21,000 additional troops Obama announced in March.

Now, this isn't as clear-cut as it might appear at first: The additional 13,000 troops, the Post reported, are primarily engineers, medical personnel, intelligence experts and military police - in other words, troops necessary to support the additional combat forces.

It is interesting to note that there was no public announcement of the additional 13,000 troops until the Post broke the story on Tuesday, although this apparently is not unusual for the White House: When President George W. Bush initially announced the 20,000 troops that made up the Iraqi surge, he didn't mention the 8,000 or so additional troops that would support them.

So, as we await the president's decision on this tough question, we'd encourage him to keep some thoughts in mind:

• Any deepening of U.S. involvement in Afghanistan is likely to involve more U.S. troops than officials announce - and, in fact, support troops often stay overseas even after combat troops begin to stand down. This, in fact, happened in Iraq after combat troops involved in the surge started to withdraw from the country.

• If the United States does commit additional troops to Afghanistan, the objective of the U.S. mission needs to be crystal-clear. A recent article in The New Republic outlined how the thinking of Vice President Joe Biden, at one time a hawk on Afghanistan, started to change after a visit to the country.

The article quoted Biden as saying: "If you asked 10 different U.S. officials in the country what their mission was, you'd get 10 different answers." This is a sure recipe for failure.

• Despite the lofty international goals of the United States, our record at nation-building has been - well, let's be generous and say it hasn't exactly been spotless. And remember that there are real questions about the ability of the Afghan government to be a functioning partner in efforts to stabilize the country.

Obama is said to be seeking advice from an array of advisers on this matter. The debate in the White House supposedly covers "a continuum" of opinions, The New Republic reported. That's good. The United States has legitimate interests in Afghanistan and throughout the region, but a bungled decision here likely will reverberate throughout the entire world.