Four-dollar gasoline has the pushed the price of energy to the top of the American mind. But the price would go a lot higher if someone applied pressure to one of the key chokepoints in the global energy pipeline.

That's the message from New Scientist, which this week examines vulnerabilities in the worldwide oil supply chain. The magazine's message is dire: A lot depends on oil, and oil depends on a few key transport and processing locations.

"Most industrialised countries keep an emergency reserve as a first line of defence, but in the face of worldwide panic buying this may not be enough," writes Ian Sample in the New Scientist article (behind a paywall). "Countries in which the oil runs out face transport meltdown, wreaking havoc with international trade and domestic necessities such as food distribution, emergency services and daily commerce. Without oil everything stops."

The global energy supply chain is incredibly complex, but much of it is channeled through a few key points (see below). Disrupt traffic or processing in those points, and terrorists or other adversaries could cause oil to rise as high as $250 a barrel, up from today's crude record-setting level of $143 a barrel.

The New Scientist report is based on scenarios from U.S. national security role-playing games. Those simulations suggest that even the perception of a supply chain disruption could drive a run on oil that would have disastrous consequences.

The latest version of the simulation, which is called "Oil Shockwave," was run last November with former Treasury Secretary Robert Rubin leading the exercise. According to New Scientist, that exercise (.pdf) found that "a simulated 1.2 percent disruption in global oil supplies caused prices to rise by 75 percent (from $95 to $165) in just four months." Given that the price of oil is now $143, that tiny decrease in liquid fuel availability could drive oil past $250.

Below, we detail the five nodes in the energy distribution network that, if seriously disturbed by accident or design, would make a mess of a once-orderly global system. Are there others? Let us know in the comments.

__1. Enbridge pipelines __(map): This array of crude pipelines pump 2.2 million barrels of oil into the United States per day, which represents about one-fifth of the country's daily imports.

Back in November, an accidental explosion in Minnesota shut down the pipeline, effectively halting one-fifth of U.S. oil imports for days. (A tiny piece of the pipeline is pictured above.)

__2. Abqaiq processing facility (pictured above, map): __The

Abqaiq processing facility, located near a Saudi megafield of the same name, desulphurizes two-thirds of the country's oil. That's already made it the target of one thwarted attack in 2006. Over the past six months, Saudi police have rounded up 700 people accused of plotting oil-related attacks, according to an AFP article this week.

A variety of other processing facilities and refineries could be major targets, like Venezuelan and South Korean refineries, but Abqaiq would be a mighty large wrench to throw into the global machine.

3. Ras Tanura offshore oil terminal (Google Earth map)__: __An incredible 10 percent of the world's oil goes through the oil terminal at this huge Saudi ARAMCO facility in the Persian Gulf, according to the New Scientist article.

4. The Strait of Hormuz and 5. The Strait of Malacca: Almost 20

percent of total daily oil production, 16 million barrels, goes through the Straight of Hormuz, which links the Persian Gulf and the Arabian Sea.

At its narrowest point, near Dubai, it's only about 20 miles wide. The

Straight of Malacca, between Sumatra and Singapore, is even narrower at less than two miles, yet 15 million barrels of oil (18 percent of global oil) pass through it.

The New Scientist describes a chilling scenario to jam these key points in the global infrastructure. "One scenario being suggested is that hijackers might commandeer a liquid natural gas tanker plying one of the shipping routes, load it with explosives and use it to ram an oil tanker. If this floating bomb produced a burning oil slick, it could render the passage impassable for months, tipping the global economy into crisis as alternative routes would fail to make up the lost supplies."

Those are just five spots in the world's energy infrastructure that could be vulnerable to attack or disruption. There are plenty of other important pieces of the energy economy we could be looking at like:

__What other energy nodes, in the US or abroad, should we be worried about? __

WiSci 2.0: Alexis Madrigal's Twitter , Google Reader feed, and webpage; Wired Science on Facebook.