An armistice is a formal agreement between warring parties to stop the fighting but this is not necessarily the end of a war. A key aspect of an armistice is the fact that fighting ends with no side surrendering. For the end of war, a peace treaty has to be discussed and agreed upon for the two countries to officially end the war and a peace treaty has still not been discussed for the 1953 Korean War Armistice Agreement so technically, the Korean War is still going on today.
Now that we've cleared up some confusion, we can talk about South Korea's tactics and means of victory during the war. With South Korea's alarmingly weak defense and their enemy getting closer and closer to taking over the whole peninsula, they turned to their allies for help. During the war, the South Koreans fought with the major help of the United States and other United Nation member countries. Those allies supplied their air forces and other armaments as well as sent supplies and men to the region and it was with their help that the tides began to change for the South. Air, land, and sea forces were sent to support the South Koreans but the real help came from the air force. Now with help, the South's air force was far more superior to the North's and victory fell in the hands of the South Koreans. Air attacks against the North's strongholds, sabotages to their supply lines, and the air support of ground operations helped the soldiers retake South Korea and invade North Korea. The U.S.'s strategy was mainly to use aircraft to attack the enemy's air efforts, provide support to ground forces, and to interrupt the North Korean supply chain. They also delivered personnel, supplies, and bombs by parachute and an interesting observation this museum discovered was helicopter use increased significantly in the Korean War as they were used for transportation, medical evacuation, and search and rescue.
With the South Koreans gaining more and more land each day, a lot of mixed feelings grew.