The USMC of 2023 is such a weird organization.
It's not. Battle Force 2030 brings USMC closer to its roots and the general idea of what a "marine" formation should be. It's everything that came before that was an aberration.
First of all USMC is distinct from the Army not just in terms of doctrine but also in terms of legal rules under which it historically operated.
Department of the Army was created in 1947 along with Department of Defense. Before then only the Department of the Navy existed as a cabinet position and Department of War was created only for the express purpose of waging a war under authorization provided by a declaration of war by Congress. US Army was legally subordinated to the Department of War but USMC was part of the Department of the Navy - a permanent department, authorized by the US Constitution - and as such operated within the purview of the President without the need for authorization from the Congress. This is why USMC could be sent into combat without declaration of war, as in legal terms it was part of the Navy. This is also why USMC serves as guard at the White House. They're "Presidents army" as opposed to "Congress' army".
USMC therefore served as "rapid reaction army" for majority of US history but during that time it mostly served as light intervention force with emphasis on capturing port infrastructure which would be then used for naval operations. The modern doctrine of amphibious landings was created as a more efficient way of performing their primary mission. Instead of capturing heavily defended ports by direct assault from the sea, marines would land at a distance and capture the target attacking from land.
Once deployed they would also be used as primary intervention force. But that never assumed large operations because before WW2 the distinction between "war" and "not war" was observed. As soon as "not war" began to look like "war" political forces in Washington pushed for de-escalation or declaration of war.
Tanks and aviation came as consequence of expanding of the scale of operations. During WW2 USMC was expected to fight a larger land campaign over longer period of time on its own, without Army's support. Because of the scale of war in the Pacific they were capturing and holding not just port facilities but entire islands and archipelagos. For that tanks, heavy artillery and aviation was necessary and USMC grew into a parallel army, not just an amphibious rapid reaction corps.
After WW2 that full-spectrum capability of the Corps became very convenient considering that the legal authorization for the use of Army and Marines remained unchanged.
Compare the size historically:
- 1939: Army - 190 thousand, Navy - 125 thousand, Marines - 20 thousand
- 1945: Army - 8,26 million, Navy - 3,38 million, Marines - 0,47 million
- 1954: Army - 1,4 million, Navy - 0,7 million, Marines - 0,23 million
- 1972: Army - 0,8 million, Navy - 0,6 million, Marines - 0,2 million
- 2001: Army - 480 thousand, Navy - 380 thousand, Marines - 170 thousand
Marines became a second Army because of legal convenience, not because it is what they were meant to be or wanted to be. It was consistently a major problem for the Corps which battled reduced budgets while being given the same missions as the Army. After GWOT brought permanent authorization for use of the military the question of USMC continuing as a separate branch was raised regularly because what's the point of funding a separate Army when there's an Army already being funded?
China gave Marines the excuse to turn back to their roots and to present itself as an unique solution to a problem which the Army is poorly prepared to handle by design. In political terms it was a masterstroke because it allowed USMC to double its budget. It was
23 billion in 2017 and 49 billion in 2022. If the purpose was just to get more money then it is a spectacular success.
Tactically and strategically it's also the correct decision and the general idea behind BF30 is sound. People have trouble understanding it because they don't understand operations and logistics and are too accustomed to the idea that a marine is just a cooler army grunt because that's what they've been in entertainment.
Per Battle Force 2030 US Marines are a
land force for enabling of naval operations. They will do whatever is necessary for that purpose so I'm half-expecting ASW-enabling operations as well over time. Whenever USN needs to use an island or a strip of land as USN asset they send the Marines.
Fundamentally USMC became a second army because during WW2 they fought an army - the Japanese Imperial Army. Now USMC is supposed to fight Chinese navy and everyone is confused that their new equipment is a long list of assets for striking infrastructure supporting enemy naval operations or sinking transport ships.
This change in USMC structure and doctrine is so far the only smart thing Pentagon has done since they began to shifting their strategy to WestPac. And considering the role of Indonesian and Philippine archipelagos as potential theaters of operations it is a very smart thing indeed.
And this is what PLAN should do with their marine corps as well. It's better to have dedicated PLAGF brigade doing the heavy fighting on land, and keep PLAN marines as a beachhead force and instead focus on becoming BF30-like and counter-BF30 formation. It will simply become a necessity with USMC adopting this posture. You can't chase off a small mobile missile unit with an amphibious mechanized battalion.