Country defaults lighting the Forex fuse?

There is now talk of run on countries. The countries in question are Iceland, Hungary, Pakistan, Ukraine, Belarus, South Africa, Argentina and South Korea. Have a read here:

Peston's Picks: Now there are runs on countries
Naked Capitalism: Is another Emerging markets Crisis in motion? (Note interesting comments particularly by Richard Kline)

The risk is enhanced by possible political response. The breadth of possible political response of these set of countries is wide as ever. This will no doubt exert pressure on Forex markets. So what will give first.

I have believed in dollar weakness all along. Initially I thought it will be the China RMB USD friction that will trigger it. But increasingly I suspect the wear down will happen from Euro and GBP side. In other words - a European slowdown can visibly translate into Euro weakness more easily than US slowdown reflecting in USD weakness.