<P> After these reversals of fortune , which saw Seoul change hands four times , the last two years of fighting became a war of attrition , with the front line close to the 38th parallel . The war in the air , however , was never a stalemate . North Korea was subject to a massive bombing campaign . Jet fighters confronted each other in air - to - air combat for the first time in history , and Soviet pilots covertly flew in defense of their communist allies . </P>
where did most of the fighting take place in the korean war
close to the 38th parallel