Definition: In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
Input: Washington (CNN) -- President Barack Obama will defend his foreign policy Wednesday in a commencement address at the U.S. Military Academy at West Point and lay out an interventionist, but not over-reaching plan, White House officials say. The speech comes amid stinging criticism of the President's foreign policy following a trip to Asia last month. Obama, who has carefully avoided mentioning any sort of military confrontation in his responses to the challenges in Syria and Ukraine, hit back at his critics, saying his goal is to avoid costly "errors" on the world stage. But the world waits for no man. Obama may advocate a risk-averse foreign policy, but he has a series of pressing global challenges which are likely to dominate the remainder of his term. Here are a few:Obama delivers the commencement address Wednesday at West PointHis focus will be foreign policyThere are global challenges likely to dominate the remainder of his termAmong them: Russia, Syria, Iran, the terror threat and Asia 
 Question:New concerns have also surfaced over reports that Russia and _ are discussing an oil-for-goods deal, which could violate the terms of the interim agreement, circumvent sanctions and derail the fate of the talks.

Iran