(this post was inspired by my wife, Amie, who is often much smarter than me.)
In 1994, Russia, the US, Ukraine and the UK signed the Budapest Memorandum on Security Assurances. France and China signed identical agreements in separate documents.
Identical agreements were signed with Belarus and Kazakhstan.
This Agreement prohibited Russia, the United States, and the United Kingdom from threatening or using military force or economic coercion against Ukraine in exchange for Ukraine giving up its nuclear weapons to Russia and becoming a party to the Treaty on the Non-Proliferation of Nuclear Weapons.
The Agreement required the countries (including the US and Russia) to respect the independence and sovereignty of Ukraine within the existing borders, refrain from the threat or use of force against the territorial integrity or political independence of Ukraine, refrain from economic coercion to undermine Ukraine, and to seek immediate action to provide assistance to Ukraine if they "should become a victim of an act of aggression or an object of a threat of aggression in which nuclear weapons are used".
Are we not obliged to support Ukraine?
What has changed?