Should our military branches be combined into one branch?

No they should not Sgt Joe LaBranche
The USAF was the Army Air Force in WWII.
THe USMC is part of the Navy
The USCG is part of DHS
We used to have a war Department and a Department of the Navy. Since the founding of this nation, when combat was on land and sea only, we had a Navy and an Army. As aviation developed and later space travel the need for a third Branch developed and the USAF was birthed.
I submit that the missions and requirements for an Army, Navy, and Air Force justify the three separate branches be maintained.

I think this would break the traditions each individual branch has... We don't need to fix something that is not broken (even though the military loves to do that)

A few thoughts/questions:
- Problem. What problem do we have currently by having separate military branches that would be solved by combining into one branch? Generally we have a problem and search for a solution. We do not normally propose a solution that has no problem to solve.
- 2nd/3rd Order Impacts. What second and third order positive and negative impacts would result from combining into one branch? I see more negative than positive impacts.
- Domains. Doctrinally there are now six domains: land, sea, air, cyber, space, and human. Each branch specializes in one domain (Army/land, Navy/sea, Air Force air) with some domains not having a specialized branch (cyber, space, human). Operations within each domain are significantly different so how would combining into one branch account for the major differences among the domains?
- History. American military history and capability has been built upon the premise of "not all eggs in one basket" and complementary capability/effects. Examples include our nuclear triad (subs, bombers, missiles) and our doctrine (joint combined arms).
- With all above stated, there are areas that should be reviewed to increase efficiency, effectiveness, and bang for buck for taxpayer money. Examples include: independent air capability for each service (why?) and service oriented funding but purple (COCOM) employment leads to independent service decisions to the detriment of COCOM CDRs.