For a classic example of why the Democrats have a hard time gaining foreign policy respectability, see this Matt Ygelsias post over at Tapped (via Jonah Goldberg at NRO).
Yglesias’ post is an example of the classic Jimmy Carter-style thinking that has crippled Democratic foreign policy, attacking the United States for pursuing its own interests, while simultaneously saying there is no real threat from our enemies aggressively pursuing interests contrary to ours.