[antientropic]

> with Crimea specifically called out, ironically, the United Kingdom and the United States have to immediately declare war on Russia and open hostilities.

It says no such thing (as the Wikipedia article you linked points out). The most it says is that they shall seek "immediate United Nations Security Council action" if "Ukraine should become a victim of an act of aggression or an object of a threat of aggression in which nuclear weapons are used."

https://en.wikisource.org/wiki/Ukraine._Memorandum_on_Securi...