In his address during the weekly portion Toldot in 5750 (1989), the Lubavitcher Rebbe Shlita King Moshiach explained that the spreading of Judaism and Chassidism in the world had led to the big changes that took place around that time (and continue happening with even more strength now). The Rebbe sited as an example the revolutions and overthrow of governments happening in various countries as well as natural disasters (earthquakes, etc.)
Chassidus explains that any action directed to spread Torah and Chassidic teachings brings light and holiness to the world and cleanses everything that can be cleansed and rectifies whatever is rectifiable.
It’s interesting to note the relationship of such events with important Jewish dates and Chassidic holidays, reason being that on those days there is an intense light emanating from the realm of holiness (Tanya, ch. 28).
Death of Stalin – March 5, 1953 (Purim)
Start of the collapse of the USSR – March 11, 1990 (Purim)
President Bush declares victory in Iraq – Purim 1991
Capture of Saddam Hussein – December 13, 2003 (19th of Kislev)
Saddam Hussein’s execution – December 30, 2006 (10thof Teves)
Government overthrow in Tunis (beginning of the Arab Spring) – January 14, 2011 (10th of Shevat)
The fall of Egypt’s Mubarak – February 11th, 2011 (7th of Adar I)
Terrorist Imad Mugnia killed – February 12, 2008 (7th of Adar I)
Osama Bin Laden killed – May 2, 2011 (28th of Nissan)
The U.S. officially ended the war in Iraq, December 15, 2011 (19th of Kislev)
Electoral college confirms Trump’s victory – December 19, 2016 (19th of Kislev)
President Trump declares Jerusalem as the capital – December 6, 2017 (19th of Kislev)
President Trump commutes Sholom Rubashkin’s sentence – December 20, 2017 (Last day of Chanukah)