That would be massive and probably imply full European alignment with China. Europe would lose their bigger supporter in the maintenance of their colonies. And the United States would lose its most developed industrial ally, as well as the base for operations in the Middle East and North Africa.

Although that would probably help Europe's economy get back to growth with cheap gas again, unless China or Russia are willing to become the colonial enforcers the Glorified Peninsula will never be the same again, and whatever remains of their ruling class will never accept it.

On the other hand the US sphere of influence would shrink to the north Pacific and Latin America. I don't think that's plausible, and I think in fact the new US admin should be trying to end the Ukraine war specifically as pretext to get cheap gas back in Europe and avoid anti-NATO sentiment. From that solid base they can wage war (economically or militarily) over the Rest of the World with China.