Stopping Activities Underpinning Development In Weapons of Mass Destruction Act or the SAUDI WMD Act This bill establishes measures to inhibit the development of nuclear weapons by Saudi Arabia. Specifically, the bill restricts the sale of specified munitions items to Saudi Arabia if, in the last three fiscal years, Saudi Arabia has taken certain steps towards developing nuclear weapons. Further, the bill requires the President to submit to Congress a written determination detailing (1) whether any foreign person knowingly engaged in the trade of specified weapons subject to the Missile Technology Control Regime (MTCR) with Saudia Arabia in the last three fiscal years, and (2) the sanctions the President has imposed or intends to impose against those persons. (The MTCR is an informal political understanding among states that seek to limit the proliferation of missiles and missile technology.) The bill also requires the Department of State and the Department of Energy to submit a report on MTCR compliance and a strategy to prevent the spread of nuclear weapons and missiles in the Middle East.