[Terabitten]

Ans: because the sea commander sometimes needs to occupy land, and he needs to do it on his own schedule, not that of the chief of staff of the army.

Help me out here, but has a Navy admiral has ever ordered a Marine operation to hold land (maybe a port seizure that I'm forgetting about somewhere?) without it being essentially a joint operation? The island hopping campaign of WWII comes to mind as a possibility, but they were still conceived and planned as joint operations.

[xzins]

My memory says that Marines take land that is critical to a naval operation and will hold it as long as it remains critical.

But, I also remember that MacArthur and Halsey were in pretty solid agreement with a few exceptions during WWII.

[SampleMan]

The USMC is part of the Navy, therefore it is technically one service with two elements. Many operations have been done together, that indeed is the whole point. One such example is the battle for Guadalcanal, where Bull Halsey was in charge of the entire shebang.

There is nothing wrong with Joint, but separate missions are best left to separate services. They are then brought together to fight the battle.

[Whispering Smith]

"Help me out here, but has a Navy admiral has ever ordered a Marine operation to hold land (maybe a port seizure that I'm forgetting about somewhere?) without it being essentially a joint operation? The island hopping campaign of WWII comes to mind as a possibility, but they were still conceived and planned as joint operations."
Back then (WW II) the Marines were more of a Department of the Navy Corps and less of an independent entity. ADM Nimitz had no problem telling them where to go and when in the Pacific. Their change in status came when the Army and Army Air Corps (reborn U. S. Air Force) tried to out muscle the Navy in the newly born Department of Defense. The politicians finally gave the USMC a vote to offset the Army/Army Air Corps majority. Just put the Air Force back into the Army and many problems would be resolved.