One of the lessons from Sept. 11 is that America requires a long-term presence in those parts of the world that endanger us. This notion has become controversial, but frankly the need could not be clearer. During World War II, our disengagement from Europe while Adolf Hitler terrorized the continent proved disastrous for tens of millions. After the end of World War II, we understood that we needed to remain in the places that threatened us. America maintained a military presence in Germany for generations, as we’ve done in Japan and South Korea.

Our safety requires a long-term military presence in the Middle East because that’s where the plans to attack us are emanating. Our presence in Iraq and Afghanistan has helped us immensely in gathering intelligence, in keeping the terrorists engaged in activities there so that they couldn’t plan activities here, and in deterring other enemies from acting irresponsibly. The timing of our troop withdrawal should be based solely on a sober assessment of when our mission is completed.