United states mainly provides quality weapons to the Ukraine which EU does not have. EU provides humanitarian aid. Which is also important but without American help Ukraine will lose the war against Russia
And a lot of European weapon systems have US components, so if Americans want they can certainly freeze and prohibit supply of military aid to the point where it won't be sustainable to resist Russian assaults.
I'm optimistic in the sense that I believe that if the EU offered to pay for the weapons, then the Trump government won't mind supplying them. The issue is that it would be difficult for the EU to reach an internal agreement.
It's a bit like if Mexico offered to pay for the wall at some point... Europe should not be a carpet, it has more than enough weapons manufacturers and any additional funding should be directed to them.
The war in Ukraine has so far been good for the US and bad for Europe so it's bonkers to suggest that Europe should make things even 'worse' for itself.
> it has more than enough weapons manufacturers and any additional funding should be directed to them.
Sure, but that won't buy us the ammunition that Ukraine needs right now. For a period of time you'd need to buy Patriot missiles, 155mm shells and a ton of other stuff from the US. Then you can slowly shift to sending shells made in the EU, IRIS-T or NASMS air defence, Marders and CV90 IFVs, and Gripen fighters over time.
