As we consider the events in Ukraine, we need to take into account what happened to the country when the Soviet Union collapsed.
(Yes, I will be taking my information from the Wikipedia article. Follow the links if you don't trust the main source.)
In 1991, when Ukraine became independent of the Soviet Union, it automatically became the third largest nuclear power, with an arsenal larger than China, France, and Great Britain combined. Through agreements with various countries, it removed all of its nuclear weapons, either dismantling them or sending them to Russia. Agreeing to give up its nuclear weapons, Ukraine was given agreements by other countries, including the US and Russia, of the following:
1. Respect Ukraine's borders.
2. Abstain from the use of threat of force against Ukraine.
3. To support Ukraine if an attempt is made to place pressure on it by economic coercion.
4. To bring any incident of aggression by a nuclear power before the UN Security Council.
Not only do we have these agreements with Ukraine, we also gave them to Kazakhstan and Belarus when they gave up their nuclear weapons.
So, yes, while we are talking about a country far away, we are also talking about agreements to protect countries that have chosen to give up nuclear weapons.