For 30 years, every serious discussion of U.S. energy policy has agreed that the dominating factor is our dangerous level of dependence on imported oil. The OPEC embargo of 1973 showed how foreign nations can use oil as a weapon to wreck our economy. And the Iranian revolution of 1979, with the shutoff of oil supplies to America, showed that they can even affect our presidential elections.

So with this great threat facing us, and three decades of jawboning, what has been our national response?

We no longer rely on other countries for one of our most important energy sources; we depend on them for two.

The energy legislation being considered by Congress could take a great step toward heading off these serious problems. But once again, Congress seems to be tied up in knots and unable to act on one of the most important issues facing the country.

Through all these years of energy studies and political promises, we have sat by and watched as the amount of oil we have to import has grown from one-third of all that we use … to one-half … to more than 60 percent today. That means we have allowed our imported oil addiction to more than double since the initial OPEC embargo – from about 6 million barrels a day in 1973 to more than 12 million today.

Beyond that, we are now adding another item to our list of endangered fuel supplies. We are now becoming increasingly dependent on other countries for natural gas.

The reason is simple. Natural gas has become the path of least resistance for many of our energy needs. It has been relatively inexpensive, compared to oil. It has served as a natural replacement for oil in many industrial and home-heating applications. And the electric power industry has adopted it as the fuel of choice in building new generating stations – in large part, as a way to avoid controversies over coal-burning or nuclear power plants. By comparison, developing a gas-burning power plant has been relatively quick, easy and cheap. It’s no longer cheap – as the price of gas has tripled over the past three years. But it is still the fuel used by virtually every power plant being built or planned in the United States.

As a result, we are now burning natural gas much faster than we are producing it. What’s the solution? Just like oil: import it.

Our imported oil has largely come from Canada – relatively close, inexpensive and reliable. But Canadians are increasing their own use of gas and can’t continue meeting our demand. So we are shipping more and more into the country by tanker, in the form of liquefied natural gas (LNG). Four coastal terminals around the country are now unloading LNG to help fill the gap in our natural gas needs; as many as 30 others are being build or planned.

As they begin operating, our reliance on imported LNG will grow from about 2 percent of our natural gas usage today to about 20 percent in 2020. And what are the countries that we are relying on for this important fuel, affordably and reliably? Algeria, Nigeria, Saudi Arabia, Malaysia, Indonesia – many from the same troubled part of the world that is causing questions about the security of our oil supply.

Increasing our use of imported natural gas is in effect a double-or-nothing bet. We will have twice as much at stake, if there is an international energy crisis. We won’t just be sitting in long lines at gas stations, the way we were in the ’70s, but we’ll also be shut out of our jobs, because the factories can’t operate and the schools and office buildings can’t be heated. And we will be twice as far behind in achieving the energy independence that – everyone agrees – must be one of the country’s most pressing priorities.

The legislation now waiting for Senate action could finally set us on a course that could lead us out of this great jeopardy. It allows more production of U.S. oil and natural gas on federal land, to cut back on imports. It encourages clean-coal technology, which can generate electricity with a greatly reduced impact on air quality, and advanced nuclear power, which will be more reliable, less expensive and even safer than our current nuclear plants. And it provides incentives for the alternative energy sources that could make a much greater contribution, including solar power and wind.

We can’t afford another decade of dither. Even by the time these initiatives take effect, our reliance on other countries will probably have reached 75 percent for oil and 20 percent for natural gas. Additional delays would make matters even worse.

It’s time to stop the analyzing and complaining, and take action. And the ball is in the Senate’s court.

Donald A. Grant, Ph.D., P.E., is R.C. Hill Professor and chairman of the Mechanical Engineering Department at the University of Maine.