That’s an excellent post. I would caution, however, that there is an enormous danger in what you’ve described. There is going to come a day (you can mark my words on this), when a private company such as Xe Corporation will be capable of doing far more than just “perform all sorts of low level functions” on behalf of the U.S. government and other governments around the world. I believe it is only a matter of time before this kind of arrangement leads to a scenario where Xe Corp. or some other variation of it has all of the military capability it needs to conquer or destroy entire nations . . . and yes, that includes the United States of America.
WW III is all about taxes?
That is one of the reasons the FFL has regular French Army officers as leaders. Xe is somewhat different because it tends to recruit from prior service US military elite forces, the vast majority of whom are extremely loyal to the US, if no longer the US government.
The British Army has long experience with what amounts to “foreign” regiments in their colonial forces. However, these regiments were in practice fiercely loyal to Britain. The Sikh regiment, for example, now in service in the Indian Army, is perhaps the most highly decorated regiment in the world, and fought for the British in both WWI and WWII, earning numerous Victoria crosses for bravery, and the British still recruit Gurkhas from Nepal to serve with the Gurkha regiment (the Brigade of Gurkhas).
The FFL does have the mark of shame of having once tried to overthrow the French government. But that is why one of the cardinal rules of mercenaries today is that they must be garrisoned offshore, with both their logistics and transportation provided by the regular armed forces.
One advantage a “US Foreign Legion”, is that we could recruit from some of the top military talent from around the world, not just US citizens. And there is a huge number of potential mercenary soldiers who would see this as a very prestigious organization to which to belong.
Their deployment would have to be by bilateral treaty, such as the US made with numerous countries to avoid persecution by the ICC of our military forces and leaders. As a mercenary organization they fit in a shadowy legal area, so would to a great extent have to operate under either US auspices or those of our close allies.