In Time, Douglas Macgregor does his level best to persuade readers that the US Marine Corps is something the Obama administration could easily cut from the budget:
The Marines as currently organized and equipped are about as relevant as the Army’s horse cavalry in the 1930s and the Marines are not alone. They have company in the Army’s XVIII Airborne Corps.
But, first, let’s examine the Marines.
In truth, the Marines have a low-end warfare niche, but a very small one for extremely limited and unusual types of operations.
[. . .]
The capability to come ashore where the enemy is not present, then, move quickly with sustainable combat power great distances over land to operational objectives in the interior, is essential. The Marines cannot do it in any strategic setting where the opponent is capable (neither can the XVIII Airborne Corps!).
The Marines cannot confront or defeat armored forces or heavy weapons in the hands of capable opponents. Nor can the Marines hold any contested battle space for more than a very short amount of time, after which the Marine raid or short stay ashore is completed.
Adding vertical-and/or-short-takeoff-landing (V/STOL) aircraft like the F-35B, to compensate for the lack of staying power and mobility on the ground is not an answer, particularly given the severe limitations of VSTOL aircraft, and the proliferation of tactical and operational air defense technology in places that count.
The real question is how much Marine Corps do Americans need? The answer is not the 200,000 Marines we have today.