One knock on Governor Romney as a potential "Leader of the Free World" is his apparently thin record on foreign policy (another source claiming the same thing and another one). The link above shows how he's been "working on it" lately.
Most Governors will always get this critique when going up against Senators in elections for POTUS.
Here are a few sources about Romney's. This Boston Globe article reviews his meetings in Boston with many world leaders.
However, Gov. Romney does have significant international experience. How well this translates into good foreign policy is obviously a matter of debate. Consider the following:
He lived in France for 2 1/2 years continuously as a missionary from age 19-21. Having done similar missionary work myself in Brazil, I can attest that this does help open one's eyes to the fact that the world is more than our country, that great and evil people live in every land, and that we are all brothers of the "human race."
He was CEO of an international company (Bain Capital).
His involvment with the Olympics has obvious international experience. Besides the SLC games, he has since been to Athens in 2004 and Turino earlier this year where he was involved in IOC events and even received an award for his work with the SLOC.
He's travelled to Iraq, Afghanistan, and Gitmo recently (obvious moves to bolster his credibility on the GWOT and foreign policy in general in preparation for his candidacy)
He's in tight with Gov. Leavitt from Utah who is somewhat of an expert on Chinese foreign policy.
Mort Kondracke seems to think that Romney has great potential as far as foreign policy goes (and most policies in general)
In his 1994 campaign vs Kennedy for the Senate seat Foreign Policy was brought up (Take this for what it's worth since it's from a piece called "Kennedy Should be Re-elected"):
"The contrast between Kennedy and Romney is most clear on foreign policy issues. Kennedy supports the approach used by Bush and Clinton; in other words, a multilateral approach designed to foster global cooperation to bring stability and order to the world scene. Romney has announced that he would not support such a policy, and would scale back U.S. involvement in world affairs to the point where we would only act when U.S. lives, territory, or the economy were at stake."
A lot has changed since 1994 of course, but at least Romney has studied the issues in depth and developed "foreign policy" stances previously.
Also, he's VERY strong on the related issue of Homeland Security and is looking strong on Immigration too.
I don't list these things to say that he's the ultimate "foreign policy master", but I think that some people may be selling him a bit short on this issue. I'd love to hear from others what their opinions of whether a Mormon mission, running the Olympics, and/or running an international company are credible "foreign policy" experiences.
Chime in please.