Thanks for the note, Elendil’s Heir.
Most powerful for the time, now; even considering how gigantic the USN was at the end of WWII. Here’s the wiki on the number of warships each country currently possesses. Note the USN is easily as large as all of the other countries’ navies put together, never mind the qualitative differences in favor of the USN. The networking between platforms today, that is pretty much an effective monopoly of the U.S. (and maybe U.K. forces), is an even greater multiplier.
(Yes, other countries have satellites and networked forces too, but I don’t see their capability having the resiliency of the U.S’s, should the various U.S. armed forces decide to remove said capability. No, I don’t have a cite, other than to point to the example of Iraq during Desert Storm and OIF. The ability of the U.S. to form an electronic order of battle through various SIGINT measures and then neutralize said order of battle is profoundly effective, and largely unpublicized.)
If and when submarines and drones ever start talking to each other effectively, e.g., if a submarine becomes capable of taking the feed from an AWACS or an emplaced hydrophone array and synthesizes that input with the feed from its own sensors…look out. Hey, when you spend several trillion dollars (the 2010 budget allocation for the Department of the Navy was $150 billion, excluding the USMC.) over 65 years (counting from NSC-48 to the present), you tend to get something flashy…
Here is a link to, among other things, the Royal Navy’s size in 1945. And here is the USN’s assessment of its own strength in August 1945. I doubt apples are being compared to apples, but here’s my quick n dirty comparison between the RN and USN, 1945: (The formatting’s going to suck, sorry.)
Carriers (rolling CVEs into CVs): RN: 58; USN: 99.
Battleships/Capital Ships: RN: 5; USN: 23.
Cruisers: RN: 35; USN: 72
Destroyers: RN: 277; USN: 377.
Submarines: RN: 178; USN: 232.
Again, these aren’t broken out further by quality/age/effectiveness. I don’t have the time to go through some of, e.g., Dunnigan and Nofi’s quantification’s of relative military power for the period, but I submit to you all that I think today’s USN is more of a relative world-beater than the USN of 1945.
Here’s where it gets tricky. I don’t know how the smaller escorts: DE’s, frigates, corvettes, are being labeled. The USN link breaks out an additional 361 frigates and 1201 patrol craft. The RN link doesn’t. I still think the qualitative differences between the USN of today vs. everyone else trumps the large, vast number of support ships the USN had back then, even if you count the giant number of vessels operated by the Army as USN power.