ok,, if you must
Korea is not the 'normal' pattern of american imperial "progress"
and, dont make the mistake as the liberals do ,that if the Kim's and the North were jsut left alone, they would be a peaceful nation!! that is such utter Polyannish dreaming there!
the Kim dynasty's sole prerogative since the end of open hostility in 53, has been to harass and usurp South Korean authority. in the 60's they openly attacked American and ROK army patrols in the DMZ routinely. They attacked the South's Korean Presidential residence (the Blue House) in Seoul in an attempt to capture or kill the south's president.
they bombed passenger jets in the 80's. the routinely have and still do infiltrate spec ops teams into the south to spy and map attack routes/defenses
they have and still do assist foreign nations in suppressing democratic movements' Khaddafi used North Korean army troops to help defeat Libyan rebels in the 80's; Assad in Syria is using them now to fight Syrian rebels--not ISIS.
they have no interest in peace-even with russian and chinese assistance for civilian projects and endeavors, they resist and turn nearly every form of aid from anyplace to military use.
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we were "assigned"-among the other allied victors of ww2, the mission of accepting the surrender of japanese forces in korea south of the 38th parallel (the same for french forces in vietnam--acccept japanese surrender south of the 17th parallel with Nationalist Chinese forces (the Chiang Kai Shek bunch) accepting surrender north of the 17th--a mission inherited by the communist chinese a few yrs later) with the Soviets accepting north of the 38th
both the Soviets and Americans/allies decided it was necessary to remain in their respective portions of korea to help administer the rebuild and start up of the county after being under japanese rule since 1910 and agred to nationwide elections that never truly happened
in '47 ,most american combat forces left Korea with only a very small, lightly armed force of trainers left to train the new south Korean constabulary.
occupation troops remained in japan though they were also not prepared/equipped for combat (when ordered to deploy from japan to korea, many individual and crew served weapons were unserviceable having been rusted shut or so deeply packed in cosmoline for storage that it took hours to get it ungreased)
the UN asked america and any other member nations to go to the south in 1950 to beat back the north's invasion
the russians and Chinese never intended to honor the agreement they signed with the other ww2 allies over korea, they had started building an offensive military from nearly day one. they built it out of the former Soviet and Chi Com ethnic Korean units that had fought in Manchuria against the japanese and in europe against germany. Kim Il Sung was a lower ranking soviet officer whose russian superior commisars thought showed socialist promise
back then-this was considered expansionist aggression by not just Kim's north but also by the chinese and soviets. intercontinental capability was not a prerequisite considered before a nation was considered a threat
america and the west wanted to challenge the communists, but did not want to risk another war that involved killing white ppl in europe so they made their stand in asia where "lesser" yellow ppl would die.
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as to the 'dwindling' of us forces in korea, well ,actually, it had started in the 70's when Pres Carter ordered the Army's 7th Inf Div to withdraw from korea along with its supporting units
in the late 80's- tactical nukes were withdrawn
in 1991, the US army gave up all of it's DMZ patrol missions and firebases to the ROK Army, the 2ID's 3rd bde was also diminished but not removed.
in the later 90's, the 3rd bde was removed
in 2004, the 2nd bde was redeployed from korea to iraq then went to ft hood afterwards then ft lewis
now, most of what remains in korea from the us army of any importance is a MLRS artillery BDE, 2 PATRIOT air defense missile bde's, an attack helo bde and then some infantry and armor units to serve as force protection for these assets.
the us maintains only a very small offensive capability in korea in the form of the mlrs and attack avn bde's
additionally, all forces,except the mlrs unit and their protection, have been withdrawn south of Seoul to a brand new base that is even south of Osan air base! no more "i was on/near the DMZ" for us soldiers unless they are part of the mainly ceremonial unit at Panmunjom.
that is massive force reduction. not just in the last 20 yrs but in the last 45 as well
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as to the rest of the world and our "adventures", yeah, you should already know i agree with you