Well, what's the denominator common to these aforesaid world leaders?
2024 is one of the biggest election years in the history of democracy. As far as the Coalition is concerned, America elects a new president and parliament. National elections will also be held (or already have been held) in Belgium, Britain, Bulgaria, Croatia, Lithuania, Portugal, Romania and Slovakia. 450 million Europeans will elect a new European Parliament, and a new European Commission will be appointed. Last but not least, one quarter of Germany will go to polls in a vote that could potentially lead to the ousting of the German Chancellor.
They do not wish to be associated with the war in Ukraine right now, either because a significant chunk of their electorate opposes aiding Ukraine or for banal psychological reasons (bad news don't win elections). How is Zelenskyy going to get his message heard if not by shouting?
And this is why I decry a lack of strategic foresight, by the way. Had Western leaders truly realised or accepted the kind of situation they are tasked with handling, they would've made Ukraine a priority on their agenda. We are in a pre-1990 geopolitical landscape, but our leaders don't act accordingly. I'm not suggesting we should go back to the 1950's and revisit the red scare era, but frankly, analysing the policies of the "collective West" towards Russia I can't help but notice only the leaders of Estonia, Latvia, Lithuania and Poland even use the term "enemy" to describe Russia i.e. a country whose regime and state media regularly voice threats of invasion and nuclear annihilation against us.
The lack of commitment is obvious, and like I said, I wholly understand Zelenskyy's frustration. Ukraine trying to stay on friendly terms with e.g. Slovakia goes to show that his anger really is about being kept in limbo. It would be easier for him to deal with being cut off from support than being promised a support condemned to materialise only after Western leaders have sorted out their own petty squabbles.
The current military topography of Europe reminds me of the history of the 1400's, when the Ottomans ran roughshod over much of the Balkans with the declared goal of conquering the entire continent. Time and time again did local leaders (like Stephen of Moldavia or Albania's Skanderbeg) ask for help from Western peoples (after having proven their ability to temporarily stop the Muslim onslaught, no less), but rarely they received more than token support. (That era even had its own Hungary and Turkey in the guise of a French king allied with the Sultan). And what happened? Most of the Balkans fell under Turkish rule (for the next 400+ years in some cases), and the tide would only be turned in 1689.
Now, I'm obviously not suggesting that Russia is on the cusp of acquiring local hegemony, but it is bizarre to me how the West appears willing to risk a major international war and catastrophic economic penalties over efforts which are moderate in comparison.