Despite the peace bubble of MAD - nuclear weapons - the newly elected president of Brazil just spelled it out "The last time there was a series of competitive devaluations. . . it ended in world war two.”
The world is in a classic crisis of overproduction - or what Martin Wolf has alluded to as weakness in global demand. Within capitalism it is only the destruction of capital, and mass bankruptcy, that can restore 'health' to the system. This is politically impossible domestically - we do live in a world of nation states - and so must be foisted off on rivals. For now the losing side is the United States, who also happens to be the predominant military power in the world.
The U.S. ruling class can't give up militarism - it has no choice but to press onwards because in every other arena it is losing or its advantages are being rapidly encroached on.
1'Brazil ready to retaliate for US move in ‘currency war’' - FT
2'The war recovery ?' - Broder
3'China and Germany unite to impose global deflation' - FT; Wolf