The OneWorld Network is a news and community portal for non-governmental organizations and non-profits and they have assembled an election site that does a great job of comparing and contrasting the candidates positions on foreign policy issues:

U.S. presidential candidates McCain and Obama would each make major changes to the national security and foreign policies carried out by the Bush administration, but their ideas of change are very different, says the executive director of the Center for Arms Control and Nonproliferation. [...] The following analysis is based on several indicators: the candidates’ U.S. Senate voting records; their national security platforms as laid out in articles, op-eds and speeches; and their responses to queries in debates, public appearances, and questionnaires. Although campaign pledges and voting records do not always accurately translate into actual policy, they can provide important clues as to the future president's inclinations.

Foreign policy issues covered include: the Iraq war, Iran policy, nuclear weapons, missile defense, and North Korea. The issue summaries are fully linked to source material and comments from registered members of the site are welcomed.