<p>I think noone knows the real answer because noone can look in vlads head.</p><p><br></p><p>One interesting thing is that oil &amp; gas fields where discovered in the black sea, on the southern coast and on crimea. More supply would definetely hurt russias economy. And maybe putin did not anticipate the sanctions that are hurting russias economy way more (with people like tucker carlson or marine le pen in the west there was good reason to believe that the west would have been shock-frozen).</p><p><br></p><p>Another thing is that putins popularity was sinking. A war to rally behind one man sounds like a plan in theory.</p><p><br></p><p>A third thing to mention: <a href="https://en.wikipedia.org/wiki/European_Plain" target="_blank">https://en.wikipedia.org/wiki/European_Plain</a> The further the border is west the smaller the european plain that needs to be defended for putin.</p>