One of the key factors that prompted the change in Ronald Reagan’s approach toward the Soviet Union during his second term was the the USSR was visibly crumbling, so he could afford to be more assertive.
The Korean war lasted about three years but the Korean Armistice Agreement only ceased-fire. It did not end the war.
Meaning that it did not end after three years. It was only announced recently as of 2018 that the war might possibly come to a close after I believe at least over 60 years.
7 SEPTEMBER 1822
..................................
The answer to this question is the
Pinckney treaty