The First Great Depression ended with Nationalism, the rise of the Nazi's and then culminated in WWII. Why would this be any different?
When people are laid off work and suffer financial distress they want to blame someone and take out their frustrations. Clever politicians direct this anger in the same way as they do religious extremism. If they can mix the two even better. Create a Boogy Man and then tell everyone to join the cause to eliminate him.
As the Second Great Depession unfolds we can expect to see some horrendous acts directed towards minorities, expats or whoever looks a likely scapegoat. This will be fueled by politicians. Hey George Bush has already done it when he told the world to join him and beat the cr@p out of the Iraqis.
Ultimately there will be wars.
Protecting nationals seems justified at first glance but drawing distinctions by race, colour, creed or passport is the first step down a perilous road.
"If you can keep your head when all about are losing theirs and blaming it on you" - Kipling