Greece is a symptom, not a cause. Excessive debt is creating a slower global economy and deflationary issues.
Today we are seeing:
1) Higher volatility and heavier volume in equities, here and overseas;
2) Big declines in commodities across the board (precious metals, base metals, energy — the Goldman Sachs Commodity Index is at a low for the year;
3) German bunds and US Treasurys at new highs; and
4) the US dollar up, Aussie dollar down.
You can call this the "risk off" trade, and it is. But it's a symptom of something bigger. It's about the debt problem. There's too much of it in the world.