Movement from India to USA used to be a one way street. Indians come over, become hyphonated Americans, to borrow Jindal's phrase, and stay. That was the norm till about 2000. Then it began to change. Most of the top grads from IITs and IIMs, no longer are coming over. Those who came, many have left, returned back to India to start companies over there. The ones who came over, learnt the system here, some got US degrees, some did not, established connections, then lots of them returned.
Not all of them returned, heck not even most of them returned. But risk-tolerance, ambition etc are not distributed uniformly, it follows the power law. So the 20% who returned took with them 80% of the risk-tolerance, ambition, entrepreneurship with them back to India.
So let Greece give up euro for drachma, let drachma fall as low as INR. It will thrive on tourism, and the Greeks coming back to start companies a few years down the road.
Germany has benefitted a lot by the economic union. Had Deutschmark stayed out of euro, its exports would have become so expensive no one could import them. 80% of Germany's exports are to rest of Europe. Capital would have naturally flowed to less expensive countries, and they would have the companies and employment restoring the balance. Greece leaving euro is going to be a bigger blow to Germany than to Greece.