Given Iran’s sizable influence on issues of critical importance to the United States—namely Iraq, Afghanistan, the Arab-Israeli conflict, terrorism, nuclear proliferation, and energy security—the longstanding Washington policy debate about whether or not to “engage” has been rendered obsolete. Continuing to shun Iran will not ameliorate any of the above challenges, and confronting Iran militarily will exacerbate all of them. The option we are left with is talking to Tehran.