Why would foreign markets dropping cause US markets to fall as well?

Creezy answered one month ago …

For one thing, much of our commerce is driven by foreign buyers of US goods. When they buy less, our companies make less money and therefore pay less taxes, which equals less money for the government to work with. That's especially important in light of this massive bailout effort by the Fed and now with what the Treasury is planning to do with the commercial paper market. The other scary thing is that these foreign markets that are just beginning to feel the noose tightening are far behind the US in terms of this downturn cycle. That means they have a much longer way to go before things start looking brighter again which could also impact the speed of a US recovery.

We're in tough times, that's the bottom line. It's time to batten down the hatches and be smart with out money.