Enemies threaten, so why do the Jews rejoice?

The Crown of Torah by Baruch Nachshon

As we enter Rosh Hashana, the Jewish new year, 5773, we see a world in chaos. So how can one explain the jubilant mood of the Jewish people?  Below are two videos. The first, from Aish HaTorah, expresses the feeling that no matter how far wrong someone has gone, a Jew can always return to his essential self and love his fellow Jew. This is the spirit of the Redemption.

The second video is from Chassidic singing star Lipa Schmeltzer, "Mizrach" (east - the direction toward Jerusalem to which all Jewish people pray). He is backed up by a special battalion for religious Israeli soldiers, the Netzah Yehuda. "East, west, up and down, north and south, gather together from the four corners of the earth...(an allusion to the final Redemption when all Jews will be reunited).

How to account for this happy mood when the enemies of Israel are plotting her destruction? Here are the words of the Rebbe:

Currently there is..an undesirable turmoil in the world...In regard to the Jewish people, however, the situation is such that the "flood" in the world is not a cause for turmoil and confusion. Most emphatically, the opposite is the case: This "flood" represents a very positive and desirable situation for the Jewish people because, "All that I have done I have done only for your sake. For what reason are you afraid? Do not fear. The time of your Redemption has arrived."
                     (Torah portion Chaya Sarah, 1991)

http://www.aish.com/h/hh/video/What-Makes-Rosh-Hashanah-Beautiful.html (suggested by A. Z. Rozenfeld)

Lipa Schmeltzer music video, "Mizrach." (as seen on Chabad.info)