Turmoil in the Middle East – most notably street riots in Egypt – is having a sharp impact on global markets. That impact is expected to be felt acutely in the U.S. by companies that do business there and by investors with exposure to the troubled region.

“Americans may feel a great distance from Egypt but it may only be far in miles,” said commodities expert Kevin Kerr, head of Kerr Trading International.

In the short-term, the Dow Jones Industrial Average plunged more than 160 points on Friday, clearly on fears tied to the escalating violence in Egypt; the price of oil spiked $3.70 on concerns that transportation channels -- specifically the Suez Canal -- could be disrupted if the protests grow in numbers and strength; gold is higher as investors, frightened by images of riot police clashing with protesters in Cairo and elsewhere, are seeking safe havens.

Meanwhile, energy-related companies such as exploration firm Apache Corp. (NYSE:APA), which gets 25% of its production flow from Egypt, and BHP Billiton (NYSE:BHP), which has substantial mining operations in the region, are getting pounded.

In the long-term, the turmoil is only adding to a growing sense of global uncertainty, coming as it does on the heels of a European debt crisis that had already left international investors skittish and questioning where they might find a little stability.

Kerr said much of the civil unrest in the Middle East can be attributed to rising food prices in the poorer nations of the region. He said the protests could have a galvanizing affect on hungry populations in Europe and even the U.S.

“Egypt is trying to tell us something,” he said. “We are likely to see more of these riots and I think the next hot zone is going to be Europe.”

A more targeted impact could be on the Suez Canal, a major pipeline for oil and other natural resources making their way from East to West. Were the turmoil to shut it down for any length of time, the results would be “disastrous,” according to Kerr.

“It has happened before,” he said. “This could create an incredible bottleneck and force crude oil prices up.”

Anti-government protestors have taken to streets daily in Cairo and other large Egyptian cities, seeking the ouster of authoritarian leader President Hosni Mubarek, a long-time ally of the U.S. In response, the Egyptian government has flooded the streets with riot police, who have clashed violently with protesters.

On Friday, the Egyptian government shut down all forms of digital technology ranging from cell phones to the Internet in an effort to block protestors, mostly men in their 20s, from communicating.

The protesters are seeking political reforms that would lead to a more open society and freedom of expression. But, just as importantly, they are seeking economic reforms that would create jobs in the region and lift millions out of poverty.

“When food prices go up and people get hungry they get cranky and are ready to topple governments,” said Phil Flynn, an analyst with research firm PFGBest.

An important question is how the U.S. will respond to the unrest. Secretary of State Hillary Clinton gave few hints on Friday in a statement that called for a peaceful end to the protests.

Markets dislike uncertainty, so investors will be looking for clues as to whether the U.S. will back Mubarek should the ruler decide to quell the protests by meeting violence with more violence. Or will the U.S. stand back and allow a new regime to emerge, one that could potentially take a dimmer view of U.S. involvement in the Middle East.

Gus Faucher, director of macroeconomics at Moody’s Economy.com, said the larger threat to  U.S. economic interests is if the unrest spreads to Saudi Arabia, where about a quarter of the world’s oil reserves are located.

But regardless of the political turmoil, Faucher believes Middle Eastern leaders, especially those in Saudi Arabia, will be reluctant to cut back on oil production.

“Over the long run, it’s not in Saudi Arabia’s interests to push the world back into recession,” said Faucher. “I would not expect any long-term disruption of oil supply because that’s in no  one’s interest.”