Don't know what to tell you, because the few things I do know (say, number of troops, equipment etc.

Re. earlier examples of international units in different wars: yes, typically, comparisons are made with the Spanish Civil Wars. Others…

Don't know what to tell you, because the few things I do know (say, number of troops, equipment etc.) are too touchy for public, and otherwise there's nothing one can confirm or tell about them with help of OSINT.

Re. earlier examples of international units in different wars: yes, typically, comparisons are made with the Spanish Civil Wars. Others coming to my mind would be wars in former Yugoslavia of the 1990s, I and II Congo Wars of 1996-2003; Iraq since 2003, Wars in Libya since 2011, Syria since 2011 etc., etc., etc.

'Problem'; the West remembers only those where Westerners were involved in larger numbers...