The Americans and the Iranians have crucial interests at stake on a variety of strategic issues in the region, and neither is capable of going alone by imposing its will on the other.
This is a good thing because while Iran cannot have a Pax-Persiana in the Persian Gulf, America can no longer ignore Iran as a major power in the region, and it must recognize that Iran has legitimate interests.
The next American president must offer Iran direct talks without preconditions, including the prospect of formal diplomatic relations and the lifting of sanctions; the prospect of new security institutions in the region in consultation with Iran.
Greater contact between Iranian and American societies will encourage democratization inside Iran. If the Cold War could end without compromising our commitment to democracy and human rights, without a bang, so can the US-Iranian contest.