1. We provided "security assurances". I'll quote from wiki:
"Under the agreement, the signatories offered Ukraine "security assurances" in exchange for its adherence to the Treaty on the Non-Proliferation of Nuclear Weapons."
"It [the agreement] gives signatories justification if they take action, but it does not force anyone to act in Ukraine." 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."
so because the senate wouldn't ratify a treaty they watered down the language to skirt congress. i see a problem with that. basically its a unconstitutional way to backdoor into a treaty. there is no iron clad commitment to the defense of ukraine...and we used the treaty to eliminate the stockpile of soviet nukes under ukraine control. playing chess a la great power games as you say.
"Until Ukraine gave up the Soviet nuclear weapons stationed on its soil, it had the world's third-largest nuclear weapons stockpile, of which Ukraine had physical but no operational control. Russia controlled the codes needed to operate the nuclear weapons through electronic Permissive Action Links and the Russian command and control system"