Although the Marines are useful, they are not really important to the military (thus the low score). Here's how a typical war (or even battle) goes: first the USAF lauches air strikes against strategic targets like enemy radar, air bases, military bases, weapons caches, etc and will continue throughout the war to continue this while also using napalm and bombings to help the army or marines, second the Navy brings cruisers, Air craft carriers, battleships and battlecruisers (if they are commisioned/available), subs and destroy sea defense while launching missiles a coastal targets so as to weaken them up to drop off Marines, third the Marines go in and kill any unlucky bastard left over after the air strikes, bombings, barrages, etc and last the Army is brought in to secure the area/territory so they can hold it, the Marins continue to push and gain land while the Army follows behind supplying the Marins as well as securing all the land (the marines can't hold/secure land because their numbers are too small, plus it's just not their job). Now if you look at these facts, you can see that the job the 170,000 Marines do could be easily taken over by the 1 Million+ soldiers in the Army. So although the Marines are USEFUL, the aren't necesarily important. Also just in case you are wondering I'm not biased as I have not served in any branch of the military (I'm only 16, not unpatriotic) and don't feel any are superior than the others truly, they are all complementary, I'm just saying if their is one branch we could stand to lose it's the Marines (who aren't really a branch but still a part of the Navy).