US Marine Corps Aviation is the 7th largest Air Force In the World

 And the US has the top 2, plus 4th place positions in the top 10:

Top 10 Largest Military Branches in the World (by number of Military Aircraft) - Flight International 2022:

1. United States Air Force - 5,217
2. United States Army Aviation - 4,409
3. Russian Air Force - 3,863
4. United States Navy - 2,464
5. People's Liberation Army Air Force (China) - 1,991
6. Indian Air Force - 1,715
7. United States Marine Corps - 1,157
8. Egyptian Air Force - 1,062
9. Korean People's Army Air Force (North Korea) - 946
10. South Korean Air Force - 898

Where is the UK, France, Germany, Japan and Taiwan?

Some of them appear, if you look at combined forces:

Top 10 Nations with the Most Military Aircraft (All Branches Combined) - Flight International 2022:

1. United States - 13,247 (5,217 Air Force, 4,409 Army, 2,464 Navy, 1,157 Marines)
2. Russia - 4,173 (3,863 Air Force, 310 Navy)
3. China - 3,285 (1,991 Air Force, 857 Army, 437 Navy)
4. India - 2,186 (1,715 Air Force, 232 Army, 239 Navy)
5. South Korea - 1,595 (898 Air Force, 611 Army, 69 Navy, 17 Marines)
6. Japan - 1,449 (746 Air Force, 392 Army, 311 Navy)
7. Pakistan - 1,386 (810 Air Force, 544 Army, 32 Navy)
8. Egypt - 1,062 (1,053 Air Force)
9. Turkey - 1,057 (612 Air Force, 398 Army, 47 Navy)
10. France - 1,055 (570 Air Force, 306 Army, 179 Navy)

If you start to rate based on quality and quantity, the west begins to shine--I include Australia, Japan, S. Korea as part of the west.

Top 15 Military Branches with the Most Powerful Air Fleets (by TrueValue Rating) - WDMMA 2021:

1. United States Air Force - 242.9
2. United States Navy - 142.4
3. Russian Air Force - 114.2
4. United States Army Aviation - 112.6
5. United States Marine Corps - 85.3
6. Indian Air Force - 69.4
7. People's Liberation Army Air Force (China) - 63.8
8. Japan Air Self-Defence Force - 58.1
9. Israeli Air Force - 58.0
10. French Air Force - 56.3
11. British Royal Air Force - 55.3
12. South Korean Air Force - 53.4
13. Italian Air Force - 51.9
14. Royal Australian Air Force - 51.7
15. People's Liberation Army Naval Air Force (China) - 49.3