A counter view is that Zelensky was simply trying to understand what Vance meant by diplomacy. As the president of the invaded nation, it has to be tough for Zelensky to watch Washington and Moscow meeting in isolation. It doesn't bode well for a lasting peace...indeed, it would be foolish for anyone in Washington to presume that Zelensky will simply toe the line and accept what he's handed by the US and Russia. Even if he did, it's likely a large proportion of the Ukrainian populace won't simply sit idly by and let Russia occupy territory. Absent an equitable peace deal, which involves all sides in the discussion, I can fully imagine a guerilla war kicking off against Russian occupiers.
That's because the US
IS the primary power deterrence against Russia. The whole purpose of NATO was to be defensive bloc against the USSR and Warsaw Pact but the US was always the primary source of deterrence.
While I haven't closely followed EU tariffs on the US, at least some of them were sanctioned by the WTO because the US was illegally subsidizing Boeing and other big companies. There are 2 sides to every story and, unfortunately, many aren't willing to listen to the other side of any argument.
Almost all NATO nations have increased defence expenditure in recent years, with most now contributing more than 2% of GDP. This chart from the Atlantic Council indicates that most NATO nations have increased defence spending, some quite markedly, while the the US (plus Italy, Croatia and Greece) has actually decreased spending:
As the NATO Summit gets underway in Washington, 23 of 32 allies now meet the defense spending target of 2 percent of GDP.
www.atlanticcouncil.org
That's because most of the democratic world, particularly "the West", were on the same page - support Ukraine economically and militarily while imposing costs on Russia through sanctions and, where possible, other actions. We'd tried to negotiate with Russia before the war but Moscow broke multiple agreements, and refused to engage with multiple diplomatic approaches by multiple western nations. Against that background, why would anyone think that Russia will act differently even if we can agree a peace deal?
By engaging with Putin, Washington took a major "left turn at Albuquerque" without consulting its Allies. Expecting the EU to provide security guarantees for Ukraine while initiating unilateral negotiations with Moscow doesn't seem like a workable plan for the US. Excluding Ukraine from the conversation almost certainly dooms any peace deal to failure. While America is the 600lb gorilla, working with Allies (rather than against them) would likely increase the potential for success in any strategic direction changes, whether related to peace or upping the military ante.
As noted above, peace at any cost isn't really peace...and it certainly won't last.