Trade treaties are treaties, and are approved only by 2/3 of the U.S. Senate.
The principle of a President unilaterally voiding an existing treaty may have started back in the Indian/Native American treaty days. In the post WW2 era, this started up again when Jimmy Carter voided treaties with the Republic of China. Some members of the Senate objected.
In Goldwater v. Carter (1979), 79-856, the U.S. Supreme Court ruled 6-3 that treaties, even though they are law next to the U.S. Constitution, and have higher priority than other laws, that withdrawal from a treaty can be done by the President unilaterally, and that the U.S. Supreme Court does not have the authority to intervene in political issues. Burger, Stewart, Stevens, Marshall, Rehnquist and Powell concurred, while White, Blackmun, and Brennan dissented, due to Constitutional issues.
And promises made by a U.S. President to other nations without a treaty, e.g. “Climate Change” promise to deindustrialize the U.S., in addition to violating the takings clause of the U.S. Constitution, have no force of law.
Right, that’s my understanding as well.