As you look at missions like theater security cooperation, the MEU is your best bang for the buck. We can go into any given area and do a training exercise, a real world humanitarian mission, and it works both to enable the country we are working with to better provide their own security and avoid us having to go in later to fix problems that may arise, or it builds good will between us such that we may be able to partner with them later or merely use their airspace when needed for actions again a neighbor.
Our supposed identity crisis is self induced. For example, we bet the farm on the JSF, and VSTOL capability. Seems to me the Marine Corps had a long and illustrious history of both maritime service and aviation service before 1985 when it got the Harrier.
We seem to have hinged our unique capability on the EFV and the JSF, both rediculously expensive and very mission specific, and as both are cut and face the chopping block, respectively, we lose our reason for being. As opposed to hinging our unique capability on the amphibious/expeditionary/maritime missions that are independent of a specific piece of equipment. Sure equipment is an enabler to those missions, but should not rely on it entirely.
If you've ever worked with the Army, and seen how they roll, ie, the massive ass behind them in the form of log trains, field kitchens, huge tents with heat and a/c, facilities, etc, etc, etc, the Marine Corps is in no way a second land army. If someone accuses of that, the better answer is to educate them on the difference between the two rather than asking for billion dollar projects to make us appear more different. I spent OIF 1 operating at a land based field with AM2 matting, sleeping on a cot in a tent with no a/c, using porta shitters, and somehow managed to make it work. The days of working on concrete, sleeping on a real bed in a can or swa hut with a/c and flush toilets came much later.