Sort of incorrect - the President is the front man for foreign matters, such as diplomacy and entering into treaties with foreign nations. The Senate has the Constitutional mandate to ratify or deny these treaties... which is why Trump was able to easily pull us out of the Paris Climate Accords. The Senate didn't ratify the "treaty" made by Oblowme. The recent pull out of the START Treaty with Russia will be interesting to watch... the Senate does have say in that one, per the Constitution. As for the Emergency Declaration for the wall, Congress ceded their authority to act during emergency situations to the Executive in 1976 (and more so since then) via laws.