Unlike the US, the EU consists of directly competing nations, that occassionally break out in violance/war. This reduces the EU's life as a group and diminishes its identity. Economic depression phases always exhibit: (i) increased violance, (ii) increased migration/mobility, (iii) a realignment of personal relationships between people themselves and to a state/infrastructure. A spectacular display of such a situation was the early medieval tribal migrations of the Volkswanderung. Can Europe be brought back to this trend today, using the current economic mess? The 1929 Big Depression did lead to some migrations in conjunction with ww2, but these were very small because of the type of intervention the US and the USSR conducted. What if this time, we the US should start up a new war, using economic policies, and for the purpose of inducing mass migration within Europe?
