The issue isn’t “foreign” (after all, a NATO troop deployment would be “foreign”), it’s the “self- styled mercenary” part. The Foreign Legion, as you point out, is a formal government supported organisation with centuries of history and experience.
I’m waiting and dreading for someone to get captured then all the hand-wringing about how the US isn’t saving the prisoner/hostage.
Yesterday was Casimir Pulaski Day, named for the Polish cavalry officer who came to the colonies to help teach the Revolutionary forces cavalry (and anti-cavalry) tactics and was eventually killed in combat.
I feel like a lot of ex military types might indeed be drawn to a conflict of clear aggressor over innocents. Lots of their field experience saw them in places where they were deeply resented by the very population they were there to ‘fight for’. Or discover their mates are dying as mere pawns in a geopolitical chess game of some sort. Many have left theatres of war, without that feeling of being victorious over evil.
Don’t you think, in their hearts, that they just want to avenge innocents against evil forces? Like superheroes get to? I do. And later 20th century wars were all sadly lacking that, in my opinion.
I can understand the motivation of veterans to get into this fight. And I can understand why Ukraine would welcome them. And I find it a little rich that any nation, willing to send it’s troops into a foreign conflict, should then prevent their veterans from volunteering, in a foreign conflict, seems conflicting to me.
If they are under the command and law of the Ukrainian armed forces, are uniformed as Ukrainian soldiers, and are being paid the way Ukrainian soldiers are paid, then they are, indeed, just volunteers, at least according to international law.
Just out of a sense of contributing to the discussion, mercenaries, according to international law, are persons who
A) Are not citizens or permanent residents of a belligerent nation,
B) Are fighting for profit as evidenced by being paid substantially in excess of what the country’s soldiers are paid, and
C) Are not within the command structure of a combatant nation.
So it’s definitely possible for a country like Ukraine to hire professional soldiers, but to stay within the law by ensuring the recruited individuals are treated as Ukrainian soldiers. It is also obviously advantageous to the recruited parties, since mercenaries are not subject to many international protections and can basically just be shot out of hand.