A Nation's Guardian Angel Will First Forsake It When A Nation Is Visited By God's Wrath

Flee ye from the midst of Babylon, and let every one save his own life: be not silent upon her iniquity: for it is the time of revenge from the Lord, he will I render unto her what she hath deserved. Babylon hath been a golden cup in the hand of the Lord, that made all the earth drunk: the nations have drunk of her wine, and therefore they have staggered. Babylon is suddenly fallen, and destroyed: howl for her, take balm for her pain, if so she may be healed. We would have cured Babylon, but she is not healed: let us forsake her, and let us go every man to his own land: because her judgment hath reached even to the heavens, and is lifted up to the clouds. The Lord hath brought forth our justices: Come, and let us declare in Sion the work of the Lord our God. Jer.50.6

Church Fathers (S.Fulgentius) say that the verse: let us go every man to his own land is best interpreted to mean Angels because Angles had special care of the Assyrian Empire and when God's wrath was visited upon Babylon the Angles went back to their own  land or Nation and forsook Babylon.

Same today - each nation has  a Guardian Angel and when God is about to punish a Nation the Guardian Angel first Forsake it then punishment follows. 

I think evidence of Guardian Angels forsaking Nation States is the recent (2015)  invasion of illegal Immigrants.

This is the reason why Nations are being overrun with invaders - the Guardian Angels have forsaken them.

Good luck.