The United States appear to trend its land power down to a size that's still sufficient to bash some small powers occasionally, but clearly not even remotely sized to take on a great power on its own (never really was).
Officially, this is the consequence of budgeting, but it's as much a consequence of inefficiency caused by a general unwillingness to tackle inefficiency at the Pentagon for decades. Their accounting is a joke, for example - and Congress adds 'pork' to the budget which benefits individual congressional districts or senators' states much more than the nations' military power.
Ambition is also a cost driver; they could in theory drop the entire strategic airlift if they were fine with the speed of much more cost-efficient sea lift coupled with civilian charter aircraft.
|The cost equivalent of a large container ship|
The United States are facing China as the only great power rival and this means they're making it official: The United States is an aerospace-naval super power* with enough land power to kick ass in banana republics or Arab countries.
This shift is a little bit troublesome, though.
Most countries lack the industrial versatility to produce enough for their military hardware needs. The United States had begun to be a huge arms exporter in 1940, helping the Allies in WW2 while it stayed neutral itself. This went on post-WW2 when the wartime surplus hardware was exported to rearming or poor countries. In the mid-50's, rearming Germany received or purchased plenty rather Korean War-era hardware (much was already obsolete) and later on NATO standardisation led to adoption of standards used by U.S. forces, giving U.S. army industries an initial edge. Foreign military sales programs meant to harden countries against the supposed domino effect of the red scare added to this. Finally, both Arabs and Israelites received plenty hardware in foreign military sales or aid - a relatively new foreign policy tool.
A U.S.Army of small size, officially oriented at small wars (= officially not meant to fight great powers or 'peer forces'), supplied by a cost-inefficient, gold-plating arms industry will yield plenty expensive products for minimization of casualties, but it's unlikely to yield much of good use for conventional warfare by countries with really small budgets.
|N-LOS missile; many of their projects are even too gold-plated for themselves.|
It's nevertheless still U.S. foreign policy to maintain many helpers / friendly countries all over the world, seated in the U.S.-friendly/Western bloc rather than in a rivalling one. Aerospace and naval power isn't going to help them much, especially if the conflict (say, border conflict), doesn't interest a U.S. TV audience.
Meanwhile, Europeans tend to go the gold-plating route as well, albeit with a little less inefficiency (except in the UK).
Where are those small powers in need of conventional warfare equipment going to get theirs from?
Keep in mind the choice of a countries' arms shopping mall was used as an indicator for its bloc alignment during the Cold War, so it's an interesting question. Egypt wasn't considered in bed with the reds when it bought Western equipment, but it was when it bought Soviet equipment and now it's still considered to be in bed with the U.S. as it still gets American equipment. Equipment is rarely equipment-only, after all; trainers and advisers come along with high tech or mere crew-served equipment usually. You cut your spare parts and ammunition supply off if you go against the interests of the supplier bloc.
The United States' military equipment procurement system is so FUBAR that ALL its regulations should be canned, its organizations be disbanded and about 80% of its personnel banned from ever working for government procurement or military contractors again (leaving only engineers, secretaries and others not tainted by (mis)management left for re-hiring).
One way to set up a new agency that would also provide a great foundation for a possible future grand army expansion would be to set up an agency tasked to motivate the development of military goods for friendly and allied nations.
This agency would not accept any input from the gold-plating experts of the active U.S. military, much less anyone who made it to flag rank in it. Almost nobody from the established DoD procurement system or the rms industry would be employed by it.
It would tour the friendly military forces, observe their exercises, investigate threat systems and landscapes and generally try to determine what these countries need for defence. Finally, it would start some development projects** to meet these needs.
The result could mimic the F-5 "Freedom Fighter", a simple, affordable fighter-bomber which already successfully pushed back against the gold-plating trend once. Similarly, the M72 LAW proved to be a bestseller for its simplicity (even though the French SARPAC was likely better).
The United States could maintain relations built on providing security without large land force on call, by doing what was likely more relevant for generations already; supply affordable military hardware to make up for the insufficient development and production capacities in many small powers.
The "affordable" angle could be further strengthened by giving such friendly foreign military sales tax credits: About a third to half of the money spent on buying American hardware turns into additional government revenues. Other countries even reach 40-60%. This is a major driver behind all those seemingly inefficient domestic arms production programs. Some countries use offset deals, in which one country buys in another and gets the promise of a reciprocal purchases in return. This way it's almost as if both bought domestically. The United States doesn't do this, and it couldn't simply because it exports much more military hardware than it imports (same with Germany and Russia). A friendly foreign military sales program which is revenue-neutral for the U.S.government could make its wares much, much more affordable and competitive.
The United States are heading towards being a rather modest conventional land warfare power, and plenty pundits are bound to claim that this isn't enough to maintain its relations (they'll likely choose to talk of "obligations").
There are other, much less straining ways to contribute to these relations, though. It is not only wasteful, but in the long term extremely troublesome to spend a large share of the economic output on government consumption such as the military. A single per cent of GDP annually more for public infrastructure and education instead of the military could yield enormous benefits, and such a shift of government resources allocation is long overdue.
*: "superpower" is fine in these areas, but I prefer to call them only "great power" in other areas.
**: Without any technological "leaps forward", but maybe with some "leaps backwards".
edit: About the army size cutting thing from the intro; an entertaining video.