Originally Posted by irishguy28

....the only one that has popped up recently is the UK. All others have been in place since March, and are unlikely to be relaxed anytime soon to the extent that intercontinental tourism is possible this (northern) summer.

And note that US tourists would have to observe a total of 28 dates of self-isolation - upon arrival at their destination, and upon return to the US. It is a requirement that returning US nationals and legal permanent residents self-isolate for 14 days on return from any international travel . Given the US's ban on all non-nationals who have recently been in Europe from entering the US, you cannot view this as merely advisory or discretionary. If the threat warrants a ban on entry, then you should observe this requirement on your return.

Until countries advise that they are once again welcoming long-haul tourists/all tourists, it would be inadvisable for anyone to set out on "holidays". There is a risk that you will be refused entry if challenged for the purpose of your visit.