Having troops under UN command does not "strip them" of their parent loyalties (to their respective services) or units, or countries, nor does it put them outside the realm of their own military justice systems.
No more than saying a NATO force does, or a NORAD force, does, or any # of other collective military or political organisations, including coaltions and other military alliances, ad-hoc or permanent.
I am not a big fan of "UN Operations" per se, I personally think coaltions with a set, mission specific objective are a better way to deploy troops in troubled areas, but I understand the mechanics of what a UN mission is, and is not.
Much of the anti-UN stuff seems to be driven by these weird "conspiracy of one world govt" nutjobs. They have no clue what they are talking about.
As for the soldier refusing to wear a "UN uniform" well several things on that:
#1 There is no such thing as a "UN uniform". The UN has no standing army, it is not a country, therefore you cant be asked to wear a "foreign uniform".
#2 There are many other uniform variations a soldier may be asked to wear, an ISAF patch, for instance. Does wearing an ISAF patch, and being sent to serve on a NATO mission, constitute wearing a "foreign uniform"?
#3 "Being asked to possibly operate against your own country" How silly. All parent nations can remove thier soldiers from any UN mission if they so desire, there is no possibility of being asked to do anything of the sort, ever. Thats just a bizzare, conspiracy driven, rant. The minute that the USA decided it wanted out of a particular UN mission (for whatever reason), its troops are out, they do not have to ask "permission" from anybody, nor does any other contributing nation.
...I have to say, I think this poor specialist was brainwashed by god-only-knows who into doing something stupid that got him into trouble. Probably some nutjobs that wanted to see him go through the ringer for their own political motives, while they sit back and watch.
I dont mind legitimate debates on the UN, but much of this "debate" is mired in a lot of weird, uninformed...crap.
...I recall an incident some years ago, bear with me here. There was a fishing boat of the west coast of Canada, off Vancouver Island that was in heavy seas and it called out a distress. Time was of the essance, and they were not sure of their exact position. As it turned out, two Canadian 442 Sqn F-18s were on an assigned NORAD readiness assignment (on the runway, fuelled, crewed, ready to go). When the call came in through the various channels to ask for the squadron to assist in locating the fishing boat, they had to ask a USAF General at Cheyanne Mountain NORAD HQ for permission to roll. He said yes, btw, and they went. I suppose that makes the US a "foreign occupier"? or the Canadian F-18s "serving a foreign govt"? you see how silly you can turn some of this stuff into?
Common sense goes a long way, trouble is, you cant legislate it.