The Budapest Memorandum was negotiated at political level, but it is not entirely clear whether the instrument is devoid entirely of legal provisions. It refers to assurances, but unlike guarantees, it does not impose a legal obligation of military assistance on its parties.[2][52] According to Stephen MacFarlane, a professor of international relations, "It gives signatories justification if they take action, but it does not force anyone to act in Ukraine."[51] In the US, neither the George H. W. Bush administration nor the Clinton administration was prepared to give a military commitment to Ukraine, and they did not believe the US Senate would ratify an international treaty and so the memorandum was adopted in more limited terms.
https://en.wikipedia.org/wiki/Budapest_Memorandum