By ourselves not easily. But such a war is World War III...everyone is getting involved.
Russia has already shown their military is subpar. Ukraine aid has still been quite limited in terms of how much of the more advanced stuff we've been willing to give them and ability to strike Russian targets. They've already got over 500,000 casualties not to mention equipment losses. They're starting with a disadvantage regardless of how Ukraine turns out. Biggest issues from Russia-owned GOPers continuing to detract and otherwise make full support difficult as well as disinformation campaigns.
The middle east is difficult. Question of getting bogged down (as per usual) as well as nuclear concerns. With NATO support on one side and opposing Russia-China support the other. Israel would likely be the biggest ally here(it is a major reason they get military support from us) and already have advanced weaponry and of course genocidal rage. Something something about enemies and enemies.
China would be the most difficult issue if already engaged with Russia and Iran. Numbers and military quality are certainly a concern. All the outsourced manufacturing would also be a major headache, honestly not certain which side would be hurt more by that economically. That said many nearby countries would probably be willing to aid in small and large ways because of dislike of China. Furthermore their last major military engagement was in Vietnam 1979 with skirmishes until 1991. So 30-40y on most Chinese commanders and infantry don't have actual battle experience. So question of quality and whether with allies we could stand up to their manpower and manufacturing capacity.
Not certain how much Africa would come into play as that'd be a real mess.
All in all, winnable or not would only be determined by actual battle. Major losses of life for all involved.
More than half of the world's aircraft carriers including Russias drydocked one.
The largest airforce in the world is the US air force. The second largest is the US army. The fourth largest is the US navy.
There's a lot to shit on the US for, the size and capability of our military ain't it unless you're talking about how it is too large.
We don't have straight manned capacity (3rd to China and India respectively). However China and India don't like one another and in fact just had a border clash not that long ago. So I'm including India against China, possibly Iran and neutral on Russia (with oil as a bargaining/diplomatic factor).
Every year the US alone has sent materiel to Ukraine that exceeds the annual total military budget of Russia which includes Russia's strategic nuclear budget. Then add all of European aid. Russia has destroyed all of it while making its military larger and more efficient by expending mostly aging assets. At the same time it put down 3 separate attempts to open new fronts against it, including flushing out the insider threats in Wagner. At the same time it has deployed Wagner into Africa to provide support to other countries. And it absolutely is maintaining sufficient force to defend the homeland against a new threat should one emerge.
Just do the math, honey.
Also, the idea that anyone hates China more than America outside of Europe is a fucking hoot!