Peace envoy's trip is part of sweeping effort to demonstrate a broader US approach toward regional peace.
Obama's outreach to Iran lifts hopes that the US and Russia can find more common ground in their bids to get Iran to curtail its nuclear program.
Many Iranians see the Nuclear Suppliers Group's Saturday decision that could permit nuclear trade with India as a double standard.
The US bid to promote a fourth round of sanctions may get lost amid sharp dispute over Russian military action in Georgia.
Monitor correspondents and experts suggest what to watch for in eight international conflicts.