So, I guess Putin was in the same situation as Hitler in 1939 when he faced the maritime blocade by the allies?
In most ways yes. But a bit different, Hitler was at the helm of a rising Germany economically and in other aspects after the great depression. I have read it argued that this rebound in economy in the 30s, even helped him cement his power (check unepleoyement numbers 1920s-1940s). At the time Germany as a "state" was not pleased about the world order just as it wasnt leading up to the first world war, it wanted more land, more influence, more resources.
In Putins case he is left with a shell of the USSR, downgraded from a bipolar world order where the USSR was a great power, to a "just a regional power" as Obama stated during his presidency. He has all the land he needs (which through corruption despite all the resources is underdeveloped), but close to zero influence outside his satellite states, and more importantly he has little power projection compared to the USSR. Nowadays he is a junior partner, relying on China and funnily enough NK.
In a big dog eat small dog world, him claiming Ukraine without the jaw to back it up is ridiculous.
Although I understand why for Russia, Ukraine of vital strategic interest. Geopolitically Russia is really f..., it does not have the luxury the US has of a perfect setup, with weaker allies to the north and south, the biggest navy x7 protecting the surroinding pacific and atlantic ocean. Just think about it, if Wagner could march from the Ukraine front to Moscow in half a day... what could a better prepared scenario do. Putin has every reason to be very worried. But going all in on your chips (almost, no full mob yet) on a play for Ukraine when you are leading a tiny shell of the USSR is foolish.
So, when I see people defend his decision, even though I agree with their assessment of the preceeding sittuation from the Russian security interest pov, I think they misjudge the situation just as Putin did. Russia today, thanks to that decision is far more unsafe than it was 3 years ago, while having lost their whole direct European customer base for their energy exports, and having lost prestige and influence in the world due to their militaries poor performance. The exact opposite outcome of what the decisionmaker was hoping for.
PS. Now depending how the Israel(potentially US) VS Hamas (potentially Iran) war proceeds, this can give a further signal to China not to test their luck. But sadly would not resolve the UN and other global organisations having lost all functionality and credibility. As other analysts have pointed out China has a window till 2028 to make a move, and I am sure they are studying their options. After that the demographics will cripple them. This is not their golden century if variables remain the same without some unpredictable event, this is their golden decade.
The future though, imo this is the century of SEA. Think the triangle between eastern tip of India, Australia, and Japan. This means excluding Japan, India and Australia. Countries like Indoenisa, Malesyia, Vietnam, Tailand, Brunei etc. 70% of world trade passess there, and some 40% of world population lives there (only demographic in the world rising with no sign of stopping). This might be that regions golden decades.