I think if Obama wants to run on foreign policy he should suggest: he will be more prudent than Mr. Romney or any other Republican would be, based on their public stances; not that he is or will be more of cowboy than Romney. This: ‘I killed Osama and Romney wouldn’t have’ seems an unproven conjecture at best, and doesn’t play up what I think is a sellable argument: ‘I am and have always been against dumb wars’. Obama has campaigned on that in the past to good effect.
With the exception of Ron Paul, every GOP candidate in the debates seemed out to suggest that he (or she) would be quicker than Obama to go the military route with Iran and maybe other adversaries. I think the coutry is still very war weary, and I think Romney and most Republicans are vulnerable to be accused that they support our troops by putting them in harm’s way as often as possible.