More Troops for Afghanistan?

A headline in today's NYTimes poses the issue perfectly:

Crux of Afghan Debate: Will More Troops Curb Terror?

My answer is, probably not. Perhaps a major buildup would suppress the Taliban for a time, but more likely it will push them into Pakistan or cause al Qaeda to shift its operations to someplace like Somalia. The occupation, moreover, generates resentment against the United States, potentially raising the likelihood of future terrorist attacks.

What we know with certainty is that the U.S. presence in the Middle East is enormously costly.

Why should we incur a large, certain cost to achieve, at best, a highly speculate reduction in the likelihood of terrorist attacks?