Here's why the new US sanctions on Russia and Iran unlikely to be a success

there are three key elements: allies, a willingness to enforce them and incentives to bargain. The absence of all three means they probably won't work with Russia and Iran

Sanctions are much in demand these days as a tool of American foreign policy.

Members of Congress want tough new sanctions against Russia for its interference in American elections. Sanctions will remain in place against North Korea, the White House says, until Pyongyang shows progress toward denuclearization. After tearing up the Iran nuclear accord, the Trump administration restored sanctions against Tehran in an effort to get a better deal on restricting its weapons and a change in its behavior. And even NATO ally Turkey faces sanctions