Why did Putin invade Ukraine?

Question: Why did Putin decided to launch a full scale invasion?

Short answer: Because Poroshenko lost presidential elections to Zelensky

Long answer:

Foreign policy is overrated.

Foreign policy can be a means, but is almost never a goal. A goal almost invariably lies in the domain of domestic politics. Therefore, when analysing the foreign policy, we must first and foremost put it through the domestic politics test. We must ask ourselves:

What domestic goal does this foreign policy measure serve?

It is ignoring the true (= domestic) purposes of the foreign policy that makes the “realist” theory of international relations so very unrealistic. So called “realists” assume that the foreign policy is motivated by the foreign concerns, while the true rationales and true purposes are almost always domestic.

Foreign policy is but a domestic policy by other means

And the war is but a radical instrument of the domestic policy.

When did Putin start preparing for the war?

Before we put Putin’s invasion of Ukraine through the domestic politics test, let’s determine the timing of his decision. Although the full-scale invasion happened in 2022, the strategic decision to invade must have been taken earlier. How earlier though?