Creating A Buffer Zone

VAYIGASH Creating A Buffer Zone Big negotiations today are all about what's going to be "the day after" the war ends, and victory is announced. One of the greatest issues is the need for a demilitarized buffer zone. This is a key component for the safety and security for any country. In the fast the Rabbis have set for the mourning of the Holy Temple, the most important one is the for the siege on Jerusalem. Why is the siege more significant then the actual destruction? How does all this apply to us, as we are not policy makers or in the military?