NATO held a conference in Estonia last week to deal with the issue of bringing Ukraine into the alliance.
NATO Secretary General Jaap de Hoop Scheffer said at the talks "that Ukraine should press ahead with defense and security reforms to gain membership to the alliance 1" and US Defense Secretary Robert M. Gates" delivered "a firm message that Russia should not fear efforts by countries in the region to seek deeper integration with the West, and must not impede their decisions to do so.2"
In the wake of the conference, Russia says it will quit the Conventional Armed Forces in Europe (CFE) Treaty if Ukraine and Georgia join NATO.
So, choose between keeping NATO membership as it is or adding Ukraine and Georgia as 'allies'. Choose between military stability or a new arms race in eastern Europe. One or the other. You might not be able to have both.