I'm not so sure anyone outside that region wants a part of this. This could be a locally contained war. The USA and Russian navies are in the area and I doubt they want to start firing at each other over this. Biden already pulled all the troops out of Israel. Looks like he would just let this unfold on its own. The North American and European public will be very vocal about not getting involved too. Israel is about to get destroyed imho. I don't believe they have nukes and will have to concentrate their firepower within their own borders soon at the approaching armies. But before all this happens we will see a sustained air battle until one side has air supremacy. And with so many nations supporting this I don't like israel's chances.