I wouldn't be so sure about that.
Norway managed to sink one of their own frigates.
https://www.navytimes.com/news/your-navy/2018/11/13/norwegia...
Germany doesn't have anything left to sink.
Japan also has a pretty sizable Navy with over 120 ships.
None of Germany's 6 subs were operational at the beginning of last year. That may have changed since, but the underlying reasons, poor planning and lack of spare parts, are still there. Only 9 of 15 Frigates were operational and the lead of their new class of frigates, the F125, failed sea trials. The Navy subsequently refused to commission the ship. Admittedly, these are not necessarily crew training issues, but crews without operational ships are not likely to maintain a desirable level of combat readiness. These issues aren't just limited to the Navy; ground forces are also in a bad state.
France and the UK are in better shape, but the Royal Navy in particular has holes in its capabilities where the US Navy is expected to fill in. They're regaining some capabilities with their new (and only operational) carrier, but it's not even clear if it has a functional air wing yet as the F-35B's they purchased only began carrier operations this past September. Another carrier is under construction, but it may be awhile before their carrier based naval aviation becomes combat effective.
The remaining European Navies are pretty small and pretty limited in what they can do. They tend to focus on ASW with some surface warfare capabilities, but are again dependent upon one of the larger Navies for air defense.
Japan may well be the most combat effective of the bunch, but that's a completely different theater of operations.
This isn't intended to be a rah-rah, USA forever sort of rant. Everyone, including the US, seem to have let things slip to the extent that combat effectiveness is becoming questionable.
https://nationalinterest.org/blog/buzz/germanys-navy-dead-26...
https://www.dw.com/en/no-more-missions-for-germanys-navy-war...
https://www.telegraph.co.uk/news/2018/02/20/german-armed-for...
It's a good thing the US is still friendly with Europe. Everything I've read about their (admittedly much smaller) navies is that they're far more professional and better run, and look at the Americans as unprofessional and even dangerous when they have to do training exercises with them.
Of course, this shouldn't be too big a surprise; just take a trip to Europe and see how much better day-to-day stuff is run. Public transit is excellent and much larger in scope, unlike America where the subways are falling apart and Amtrak is a joke. Airports are smoothly run, unlike America where they aren't even paying the security people (TSA) to come to work. Bridges in Europe aren't dilapidated and literally falling down like they are in America.