The US has tax treaties with a number of countries that modify the usual US tax position. Most of these treaties deal with income tax, but some deal with estate tax, exchange of information, or social security (totalization).
“U.S. tax treaties differ from the OECD Model in certain important respects.”
Most US treaties contain provisions that are not found in tax treaties unrelated to the US, for example Limitation of Benefits (LOB) provisions, and Savings provisions.
Any treaty question needs to be considered in light of the wording of that specific treaty, as the wording of provisions sometimes varies from treaty to treaty.