ABC News' Kirit Radia reports: On Wednesday the Obama administration will name veteran nuclear weapons expert Bob Einhorn as its top official to enforce sanctions on Iran, the same day it expects the UN Security Council to pass the toughest round yet of punitive measures against Tehran, a US official tells ABC News.. According to the official, Einhorn will be the “super enforcer” for sanctions, though it’s unclear exactly what his title will be. Einhorn is currently the Special Advisor for Nonproliferation and Arms Control at the State Department. Since the 1970′s he has held a wide range of arms control and nonproliferation positions throughout the government. On Wednesday morning the Security Council is scheduled to vote on the fourth round of sanctions against Iran. The measure is expected to pass, despite opposition from non-veto members Lebanon, Brazil, and Turkey.