Don't be so sure in your assessments of 'US weakness.' Certainly our present leadership is minor league, but the nation's technical strengths should not be underestimated.
While Russia is openly parading these new missiles for all the world to see, don't forget the accomplishments of, for instance, Kelly Johnson's Lockheed Skunk Works who among other things designed the P-51 in 90 days at the end of WWII. That was really too late to have much effect on that war, and it would soon be eclipsed by the advent of the jet fighter. Nonetheless, it was an amazing accomplishment and demonstration of American know-how.
But you say, that was 70 years ago, what about now? Good question. Some years ago the USAF retired its fleet of near-hypersonic SR-71 reconnaissance aircraft. Those in turn had replaced the venerable U-2, like the one in which Francis Gary Powers got shot down in 1960 over Russia (by an SA-2 missile). (Both Skunk Works products, BTW.) The SR-71 flew so fast and so high -- its actual capabilities are still classified to this day -- that it was immune to attack from the ground or air, and it could fly at will whenever and wherever it wanted. The Soviets could see it up there, but were powerless to do anything about it. And remember, the SR-71 operated secretly for many years before its existence was even acknowledged. (In its later days, it would be shown sometimes at airshows, I remember seeing one in the 1980s at Fairchild AFB near Spokane. There's one on static display at an aerospace museum near Portland today; if you're lucky (as I was) there might be a retired SR-71 flight officer on duty as a docent, explaining that still amazing aircraft.)
The lesson to be learned here is that the USAF would not have retired the SR-71, or shown it in public, until (likely many) years after its replacement was fully operational. From this point on, I am talking only about things that have been presumed or speculated, but are consistent with past US military history.
So what replaced the SR-71? The official story is spy satellites, but useful as those are, they have too many limitations that a manned, maneuverable system does not have. Those in the know believe that there is an advanced spy plane some call Aurora. This aircraft/spacecraft has capabilities that exceed the SR-71 by at least as much as the SR-71 exceeded the U-2, which is substantial. While the SR-71's top speed is still classified, there is some evidence that it was much, much higher than the claimed Mach 3 (about 2000 mph). Aurora then is likely able to fly in near space, from an isolated and top secret base somewhere in the middle of nowhere (SR-71s were based at Beale AFB near Sacramento, hardly in the middle of nowhere), and go anywhere anytime. It will no doubt implement the most advanced stealth technology, so it is essentially invisible. Where the SR-71 could be seen but not attacked, Aurora is essentially invisible.
It is also possible that such a platform could have some offensive capability. One never knows until one day, when Aurora is declassified. Now where would the technology for this come from? Well, the USAF has been doing lots of strange things out in the desert at Area 51 and now Area 52. Few people actually know what they are up to, though they've been out there for decades and clearly up to something that they don't want the general public to know about. Supposedly the F-117 stealth fighter was first flown out there, while it was still top secret.
Anyway the point of this is that we should not believe that the US military has been out-performed by the Russians or Chinese. They are doing things that (unlike Russian and Chinese PR) they won't talk about. There may, for example, be a fleet of hundreds of US Navy nuclear-powered mini-attack subs out there lurking in the depths, waiting to destroy enemy assets on a moment's notice with ultrafast seaborne/airborne torpedo/missiles. The US has the technology for this -- these mini-subs could easily be based in a small, unobtrusive facility in port somewhere with sail-in, sail-out secrecy. Nobody would know.
It's possible that the Russians and Chinese are all about propaganda, one of their strengths after all. That Chinese hypersonic glide missile or whatever they called it? It has to be launched from a Long March booster, IIRC roughly equivalent to a US Titan or Russian Proton -- a big, expensive rocket that takes quite a bit of time to prepare and launch. Hardly a serious weapon system, not to mention that it landed some 25 miles off target.
Russia and China are not standing still. But neither is the USA -- the difference is that the most advanced military systems of the US military are top secret. They are not putting on shows and bragging to everybody, they are doing it quietly. As has been their practice for 75 years now.