Daniel 2.21 says, "He changes times and seasons; he deposes kings and raises up others. He gives wisdom to the wise and knowledge to the discerning." (Similar thoughts are in 1 Sam. 2.7 and Luke 1.52.) So we'd have to affirm that God sometimes intervenes in the affairs of this world. The verse doesn't say that He always or often intervenes, nor does it claim that every politician, king, or president was put in place by God Himself. What is claims is that God has the sovereignty and right to intervene as He wills.

So I can say with confidence that God intervenes in the affairs of this world, e.g., politics and social affairs. Identifying where He has acted is a completely different matter, however. For that we have to know how people are praying and how God reveals His purposes through people as spokespersons for Him. In other words, if He intervenes, He's usually communicating that to someone in some way. Without that communication, accurately interpreting circumstances is difficult if not impossible.

I know a gentleman who works at the U.N. who says he has seen this (God raising up and/or deposing leaders) often.

Does God intervene in the affairs of this world e.g. Politics, social affairs?

I mean in modern history not bible times.