patrick.net

It doesn't matter what Congress or Pundits say, it is an open question as to whether the President needs ANY approval from Congress to abrogate a treaty.

The Constitution ONLY speaks of acceding to a Treaty, and is silent about their abrogation.

TWO Presidents have abrogated treaties with no vote at all in Congress: Carter in 1978 involving ROC, and Bush II in 2002 regarding the ABM Treaty

In Goldwater vs. Carter (1979), specifically about Carter's abrogation of the aforementioned US-Taiwan Defense Treaty, SCOTUS refused to rule on the case entirely, and nullified all decisions made by lower courts, effectively letting Carter's abrogation stand.