As a new round of Iran talks gets underway, the temptation in Washington — as usual, as with most issues — is to engage in ferocious debate about proper U.S. approaches to the nuclear issue. But it is important, given the degree of acrimony in American politics today on most issues foreign and domestic, to stay focused on the fact that whatever prospects we have of a negotiated deal constraining Iran’s nuclear program are the result of U.S. and international pressure dating back to the George W. Bush administration and solidly involving both houses of Congress and both political parties as well.