On August 2, President Trump signed H.R. 3364, the "Countering America's Adversaries Through Sanctions Act," a law imposing sanctions on Iran and North Korea and prohibiting the President from lifting existing sanctions on Russia. However, President Trump also issued a signing statement (actually two signing statements) in which he asserted that the law was unconstitutional. Was he right?
In part the President is correct: the provision of H.R. 3364 that declares that it is the policy of the United States not to recognize Russia's sovereignty over Crimea and eastern Ukraine is unconstitutional. The Supreme Court has ruled that the Constitution implicitly gives the President has the sole power to recognize what territories are subject to foreign governments. In contrast, the sanctions imposed by Congress on Russia on account of its actions in Ukraine and the limitations on the President's power to lift those sanctions are constitutional, because the Constitution expressly vests Congress with the power to regulate foreign commerce.