To the best of my knowledge, there are US officials - current and past - who plan their travels very wisely on account of active warrants whose execution depends on the discretion of mandarin and country. I believe Bush, Kissinger, Rumsfeld, etc have been unable to travel to Switzerland and Belgium and indeed freely within Europe.
That said, just a brief comment on Pundit's views on the possible prosecution of Blair: I think Pundit is not ignorant of the finer details of the matter and why the two cannot appear before the ICC. Even if one overcame the legal bottlenecks, look at how Bashir managed to sneak through loopholes between the South African Judiciary and the Executive. As you rightly said, any poor country that tries to play hero would end up worse than Zim. I can add that any Non Poor country that attempts would be inviting a war.
It is a jungle out there. That is why efforts such as the ICC should be supported strengthened and accepted. In his last interview before leaving office, Nyerere said his greatest success was the popular acceptance of the ideals of socialism by Tanzanians. Today even as capitalism thrives in Tanzania, they have fewer problems over land, infrastructure etc, thanks to Nyerere. We need to do the same for such institutions as the ICC
I have no problem with regional courts such as Uhuru's African Court. However would it be allowed to function if it gets serious with its work? Is Uhuru willing to submit himself to the said court or is he setting it up for his subjects and not himself or his fellow Presidents?