I recently spent some time reading about Smedley Butler. For a short period of time he commanded US Army soldiers, which I also thought was odd. Reading some things from the period I was struck by a complete absence of "rivalry" between the branches. In a few places it was difficult to know if the author was speaking about the Marines or the Army as the word soldier seemed to get used for both. It did seem the Marines of the period had a general dislike of the Navy but I didn't see too much indicating this also applied to the US Army.

Am I wrong? Or did the mostly good natured back and forth between the branches come later? Or would the attitude of a Marine in 1910 been more or less the same as today concerning the Army?

I think prior to World War II the roles of the branches were pretty defined and so no branch rivalry. The marines pre-World War II were treated as secondary to the navy so there was some resentment associated with that. The Marines in World War I were still small so they were all rolled into the 2nd army division for that war. With World War II, roles began to overlap and that has led to more rivalry. The McCain Defense Act of 1987 really upped the purple stink on the military and started mixing the services for the good natured rivalry.

My dad was an enlisted Marine for a couple of years during the end of World War II. After he got out, he returned to A&M, graduated, and was then commissioned into the regular army. He said that the biggest difference between the two services was that the Marines did a much better job of public relations. Virtually every marine outfit had a reporter or photographer embedded within it. The army was more focused on simply doing its job.

He also pointed out that, in the Pacific during World War II, the US Army captured much more territory with far fewer casualties than did the Marines. From his perspective, what the marines called "aggression" was rather simply frontal assault, which the army viewed as stupid.

In addition, as a previous poster has alluded, the marine mission expanded to almost replicate the army mission. The army mission has stayed consistent, however.

Very true about Marines v Army in WWII PTO. Far more Soldiers than Marines, even serving together in some of the most well known battles but you'd think the fighting was done by the Marines only from movies and books and such.

From what I have read it seems the rivalry was more prevalent the higher up you went. The authors of one book talking about strategy and command sent out a preliminary copy to field commanders for their review. Several responded that they were unaware of the issues mentioned in the book and didn't see it in the troops in their areas.

In the Philippines I believe most of the marines were in air support of troops. The army ground troops preferred the marine air support to that provided by the army.

To me, the Marine leadership had too much hubris. On Saipan, instead of questioning their intelligence of Japanese strength they insisted the army wasn't pulling it's own weight. Turned out there were far more Japanese in the area the army was attacking than what Smith thought.

On Peleliu, Maj. Gen. Rupertus said it would take them only about 4 days to take the island. He also held out sending in the army's 81st Division to reinforce the 1st Marine division. Some say he did this so that it would be an all marine affair. The army had to come in later.

From my readings, the main source of the "the Army isn't aggressive enough" canard came mostly from Holland Smith - whose relations with Army leaders became so problematic that he was promoted and stashed away in Hawaii in charge of training or somesuch, well away from the Army.

I don't recall reading about any such griping by Marine generals in the Solomons, or by generals other than Holland Smith in the Marianas.

I do recall reading that the Marines on Okinawa saying Army troops on the island were moving too slow, because the Marines had cleared the north part of the island (where there the Japanese didn't mount serious resistance), while the Army was struggling in the south end (where the Japanese commander had most of his troops and really nasty, well prepared positions in tough terrain). That lasted until the Marines were introduced to the Shuri Line.

Now, it is true that neither Eisenhower nor MacArthur (especially MacArthur) wanted Marines in their AO. (In the end, it didn't matter much, because there were only enough Marines for the Central Pacific anyway.)

An interesting argument has been made that the battle for Iwo Jima was valueless. Approximately 7,000 Marines were killed and another 19,000 were wounded. It posed no threat to us while under Japanese control and we made no significant use of it after capturing it.

From what I've read, fighters were never able to actually escort the bombers from Iwo Jima. That was the justification prior to the attack but never implemented. And the number of "saved lives" is an estimate based solely on the number of bombers that landed there. Surely some of those bombers might have been able to make it back to the Marianas or wherever they were based, just like they had been doing prior to Iwo Jima?

Interestingly that estimate is almost exactly the same as the number of actual Marine casualties. Was it worth it?

My dad was stationed in Guam in the AAC and was a crew chief with B-25's and also pulled duty working rotations on the crash crews of returning B-29's.
He said that having the base in Iwo saved a lot of planes and lives that could not make it back and also for medium range bombers.
I guess it would be up for discussion. He stated that if anything it gave some comfort and moral boosting to the bomber crews knowing they might stand a better chance of staying alive.