What relevance does Ukraine joining NATO, a defensive alliance, have to Russia? (Unless they are planning to attack again, which would mean the "peace deal" isn't actually worth the paper it's signed on, and is just a way for Russia to regroup for their next invasion.)
Whether you call it "defensive" or not, NATO—and the arms race it and the Warsaw Pact fostered—directly led to the Soviet Union's collapse. Recall that JFK almost started WW3 when the Soviets sent nukes to Cuba. NATO on Russia's borders isn't all that different to them.
