At the end of the korean war a ceasefire was established near the

the  seven  days  battles  were  a series of seven battles over seven  days from june 25 to july 1, 1862, near richmond, virginia,  during  the american civil war. the  seven  days ended with mcclellan's army in relative safety next to the james river, having suffered almost 16,000 casualtiesduring  the retreat.

which statement explains one of the reasons world war 1 was so much more destructive than earlier conflicts