On the one hand the US has pushed for this by weakening NATO. On the other hand what's interesting is that the EU's primary defense focus is Ukraine whose primary adversary's primary defense partner is Iran, including creator of the dominant drone that Russia uses to attack Ukraine. So while it makes sense that European countries are doing what they can to avoid being targeted by Iranian retaliation, it's a pretty sad state of affairs for Europe to not be able to do much to defend its interests (in Ukraine or the Gulf). All of this will lead to a newly muscular Europe, presumably. Which is what the US has been pushing for. But the US will have to get used to getting less red carpet treatment in Europe.