In the August 2007 issue of Foreign Affairs Journal, link to follow, Obama lays out his foreign policy platform.  It's a long and enlightening article. I think he is dead on in a lot of respects  with regard to foreign policy but some of his rhetoric with regard to Iran could have been taken from a Cheney stump speech.  A few choice quotes:

We should expand our ground forces by adding 65,000 soldiers to the army and 27,000 marines.

I will not hesitate to use force, unilaterally if necessary, to protect the American people or our vital interests whenever we are attacked or imminently threatened.

Iran and North Korea could trigger regional arms races, creating dangerous nuclear flashpoints in the Middle East and East Asia. In confronting these threats, I will not take the military option off the table.

Some might consider this kind of rhetoric to be necessary to "win the middle" and secure the presidency.  Some might even think this is sound policy.  I think this kind of rhetoric helps to feed the problem and projects America into a role that must be opposed by other powers.  Just as we cannot abide a non-friendly nuclear neighbor the world cannot fail to oppose the most powerful military force in the world if we maintain that unilateral military action is always on the table.

When Obama becomes president I hope the progressive wing of the party will actively lobby for a change in some his rhetoric.  After all that's some change we all deserve.  

http://www.foreignaffairs.org/20070701faessay86401-p0/barack-obama/renewing-american-leadership.html