During the Cold War years, 1947 until 1991, every U.S. president sought, one way or the other, to limit Soviet nuclear arsenals. Since no one, regardless of hardline rhetoric, discovered a formula for unilateral disarmament on the Soviet side while we continued to build new nuclear weapons, even the most conservative presidents came to realize that negotiated agreements offered the only way out.

Predictably, conservative Members of Congress trusted agreements negotiated by conservative presidents and often opposed those negotiated by progressive presidents, though the terms of the agreement, including verification provisions, were often very similar.

Opposition to arms control and reduction agreements focused on the untrustworthiness of the Soviet regime, the absolute conviction that the Soviets would secretly cheat, a desire not to do anything that might benefit the Soviets even if it benefited us, and an unspoken conviction that we needed the Soviets as an enemy not a negotiating partner.

If this all sounds familiar these days, it should. The same arguments are now being used in response to the agreement just negotiated by Secretary of State John Kerry with the Iranian Government.

Some principles need to be recognized. We don't negotiate with our friends; we negotiate with our adversaries. We don't negotiate with our adversaries to do them a favor; we do it because it is in our national interest. We don't negotiate arms limitations agreements based on trust; we negotiate them based on verification -- in this case, verification we do not presently possess. We do not negotiate against the interests of our allies; we negotiate with allies on our side -- in this case Germany, France, Russia, and China. We cannot negotiate unilateral concession agreements whereby we offer nothing; we negotiate using trade-offs -- in this case, careful lifting of sanctions.

Skeptical Members of Congress are insisting on detailed analysis of the agreement, which is perfectly acceptable, that is unless it becomes an excuse for endless questions about why we did not negotiate a perfect agreement that required no concessions and brought Iran to its knees.

Eventually, votes must be cast. Those who oppose the agreement for one reason or another must come up with better reasons for doing so than merely citing unachievable objectives not included and they must bear the judgment of history for the failure of a major foreign policy achievement. There are substantial risks in opposing this agreement and, in the judgment of history, few rewards.

It is interesting to speculate how the partisan lines would divide had this same agreement been concluded during the George W. Bush years. Based on the history of the Cold War years, there would have been considerable support from the Democratic side and not the solid partisan resistance from Republicans now committed to blinkered opposition to anything achieved by the Obama Administration.

This agreement to limit Iranian nuclear ambitions does not and could not solve all the complex problems represented by Iran in the Middle East any more than nuclear arms agreements with the Soviets solved all the problems they represented in the world. No plausible and persuasive argument has yet been offered as to why we and our allies would be better off without this agreement. Until it is offered, this agreement profoundly requires Congressional approval.