sabresfaninthesouth
Lifelong Cynic
I hope so seeing as how the US is usually the fallback location in case something goes wrong. They have infrastructure to support something likes this with little notice. Example, look at the New York Metropolitan Area. World class subway system, as well as trains in and out, buses, plenty of hotel rooms and they already have Yankee Stadium, Citifield, Metlife Stadium, Red Bulls Arena and if need be the Rutgers Football Stadium. Give them 6 months and they wouldn't bat an eye.
I see the US being, at best, top 5 on the fallback list. As I said in an earlier post, England and Germany, plus I would expect Spain and Italy, since those 4 countries have the top 4 domestic leagues. Add to that Brazil, who will have semi-recent experience from hosting 2014 and Russia who will have hosted in 2018. Just as an example, when there were questions about whether South Africa would be ready to host in 2010, FIFA had indicated that Germany - the most recent host - would be the fallback.
The US may have the greatest number of stadiums altogether, but what we have working against us is a) relatively few of these stadiums that have a large enough capacity are soccer specific so there's concerns about total field size, sightlines, etc. and b) the logistics of bringing that many people to the US and moving them around in a geographically very large country. All of that can be handled easily with appropriate planning, but not sure it could happen on a 6-12 month timeline like the other countries could.