The affluent suddenly cast down” brings us back to Quatrain VIII-14 and the hint that “the great credit of gold and abundance of silver” may refer to The Global Economic Collapse.

Les trois freres” I suspect is Nostradamus’ reference to the three superpowers. Obviously, if they go to war they can bring “misery and trouble to the world”.

The attack on a “marine city” seems to be the false-flag event that leads to war. As I described in Chapter Six, “the marine city” may be connected to the terrorist incident at a port city that brings Henri Selin to the public’s attention.

Nostradamus Quatrain VIII-17
Les bien aiƒez subit seront desmis,
Par les trois freres le monde mis en trouble,
Cité marine saisiront ennemis,
Faim, feu, sang, psƒte, & de tous maux le double.

Nostradamus Quatrain VIII-17
The affluent suddenly cast down,
By three brothers the world miserable and troubled,
The marine city seized by enemies,
Famine, fire, blood, pestilence, and all evils doubled.

This is also part of The Clinton Triplicate Series that follows the nuclear naval battles in the Aegean Sea. Nostradamus is certainly giving his readers a sequence of events to use as a predictive device. Notice how Quatrain VIII-17 comes back around to economic matters referred to in Quatrain VIII-14.