The three weeks between the fast days of 17 Tammuz and 9 Av are traditionally called the days of Bein Hametzarim, a reference to their being between two major tragedies, the breaching of the walls of Jerusalem and the destruction of the Beit Hamikdash.
This period is certainly a time for serious reflection on the part of all Jews who long and pray for a totally rebuilt Jerusalem and the restoration of the Beit Hamikdash in our own days. Such reflection on the fact that the sin of unjustified hatred of one Jew towards another brought about those tragedies will hopefully inspire all of us to develop better relations with all of our fellow Jews and thus secure Israel forever.