Story highlights Turmoil in Egypt over past two years has virtually halted travel by Americans

A pinch on oil passing through the Suez Canal would hit U.S. drivers at the gas pump

The most populous Arab country, Egypt's stability is seen as key to Mideast peace

As political turmoil engulfs Egypt, Americans are watching closely -- and they should be: What happens in Egypt will directly affect Americans in many ways.

1. Travel: See the pyramids along the Nile -- NOT

Egypt, with its 5,000-year history, the pyramids and pharaohs, was always a luxury travel destination for Americans but the political and social violence that has wracked the country for 2½ years has virtually destroyed Egypt's U.S. tourist business.

Now, the State Department is warning citizens not to travel to Egypt and U.S. citizens living in Egypt to leave. It also ordered non-emergency personnel and families of Americans working at the U.S. Embassy and consulate to leave.

JUST WATCHED U.S. military aid to Egypt on the line Replay More Videos ... MUST WATCH U.S. military aid to Egypt on the line 02:39

JUST WATCHED Clashes in Egypt turn deadly Replay More Videos ... MUST WATCH Clashes in Egypt turn deadly 02:58

JUST WATCHED Violence in streets of Cairo after coup Replay More Videos ... MUST WATCH Violence in streets of Cairo after coup 04:48

2. Money

Egypt is America's closest ally in the Arab world and it gets $1.5 billion a year in U.S. taxpayer money for military and civilian programs. In fact, in the last 30 years, the United States has sent more foreign aid to Egypt than to any country except Israel.

Now, that money hangs in the balance as the Obama administration decides whether to call the overthrow of President Mohamed Morsy a "coup."

Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, tells CNN: "If this were to be seen as a coup then it would limit our ability to have the kind of relationship we think we need with the Egyptian armed forces."

3. Mideast peace

The United States helps Egypt because it's one of only two Arab countries -- along with Jordan -- that made peace with Israel. If Washington pulls its aid, it could affect prospects for peace in the Middle East.

"All of these things are tied together," says CNN's Fareed Zakaria. "The aid is tied to Egypt's peace treaty with Israel, so if our aid gets cut off what happens to the peace treaty with Israel? It's a hornets' nest and that's why the administration is trying not to stir it too much."

4. Gas prices

Egypt controls the Suez Canal, a crucial sea route for more than 4% of the world's oil supply and 8% of seaborne trade. So far, the canal is running smoothly -- but increased violence could end up hitting Americans in the pocketbook.

5. The linchpin

With 83 million people, Egypt is a cultural heavyweight in the Arab world.

"The great trends that have affected the United States have come out of Egypt," says Zakaria: everything from pan-Arab nationalism of the 1950s, Islamic fundamentalism which began in Egypt in the 1970s -- even al Qaeda has its roots in Egypt and Islamic Jihad.

"Egypt is the source of all the pop music, the soap operas, the movies of the Arab world," he added, "so what happens in Egypt tends to have a much wider resonance throughout the Arab world."

Until the Egyptian military ousted Morsy, Egypt also had a claim to fame politically: a democratically elected president and his Muslim Brotherhood party. It was a message to the Islamic world that democracy just might work. Now, there's a danger the military could violently repress the Muslim Brotherhood and it, in turn, could resort to violence.

That would make the whole Mideast region more unstable -- a worrisome development for the United States.