Would the Keystone XL pipeline make America more secure or less? What contribution would it make, if any, to stabilizing our energy supplies or keeping us out of messes elsewhere in the world? Would it have an adverse impact on global climate disruption, or no impact at all? Informed people want to know.

Unfortunately, some of the pipeline’s supporters are fogging up the issue with deceptive numbers and claims, including vastly inflated job estimates and assurances that the pipeline would make America more secure.

The State Department and Cornell University, among others, have deflated the job claims. But will Canada’s carbon-intensive tar sands oil increase America’s security?

Not according to the people who know security best, including high-ranking retired American military leaders who are no longer gagged by their uniforms.

Among those invoking national security are 14 Republicans from the House of Representatives who wrote to President Obama to argue that his rejection of the project would raise “dire national security concerns” by prolonging our dependence on oil from countries like Venezuela.

A study commissioned by the company that wants to build the pipeline — TransCanada Corp. — makes a similar statement, concluding that the pipeline would give America greater energy independence with more oil from a neighbor who’s friendlier than Saudi Arabia or Venezuela. Jack Gerard, the president of the American Petroleum Institute, argues that building the pipeline will show the world that the United States is “serious about securing its energy future.”

They are wrong. There is only one certain way for the United States to achieve sustained national and domestic security related to energy. Rather than increasing our supplies of fossil fuels, we have to begin leaving them in the ground. It makes no difference what country they come from.

Listen to Army Brig. Gen. Steven M. Anderson, who oversaw logistics for allied troops in Iraq in 2006 and 2007. In an interview last December, he said, “all Americans should be outraged” about the national security liabilities of the Keystone project because it “keeps us hopelessly addicted to oil.” He continued:

I want to stop paying big oil and I want to start seeing a green economy in this nation. And big oil is pushing Keystone, and Keystone is essentially going to maintain the status quo for another 25 years. And during that time I can only imagine the impact it’s going to have on our environment and, indeed, our national security.

The firm that TransAmerica hired to assess the pipeline’s costs and benefits defined security as “a supply of oil in reliable quantities from more stable and predictable sources than the volatile regions which now dominate the global market.”

Security experts disagree. Listen to the prestigious group of retired senior military leaders — admirals and generals — who have studied America’s energy and climate security for the past five years as members of the Military Advisory Board at the Center for Naval Analysis. They’ve concluded:

Our heavy reliance on oil, especially imported oil, calls for immediate and aggressive actions to move our transportation sector away from oil and toward alternative, domestically produced sources of energy in order to improve our national security posture… The U.S. must take swift and aggressive action to reduce our use of oil…

If we measure energy security by energy prices, the Keystone project’s influence will be negligible to negative. The Canadian oil moving through the pipeline is expected to increase gasoline prices in the Midwest and perhaps nationwide as refineries in the Gulf of Mexico produce less gas so they can process tar sands oil. And as energy experts have repeatedly pointed out, more oil production in North America or the United States has little impact on the price we pay in the global petroleum market.

The American Security Project offers an additional explanation of why more oil production doesn’t necessary result in lower prices, and it applies equally well to North American petroleum:

There are two reasons why the growth in U.S. domestic production does not reduce oil prices. First, the increased production simply is not large enough, in contrast to global supplies, to make a difference. Second, for the most part, the new oil production brought on line over the past five years has a high extraction and investment cost, coming from either shale oil formations or deep offshore.

This last point — the costs of extracting oil and gas today — deserves explanation. Much of the oil we’re trying to extract now is different than the oil we consumed in the past. The cheap and easy-to-reach supplies are disappearing.

Taking their place are “unconventional” oil and gas that generally come from harder to reach and riskier places. That’s why horizontal drilling and fracking have become so popular. It’s why the Deep Water Horizon was in deep water, and why it got it into deep trouble.

The extraction and processing of unconventional petroleum — whether it’s made from tar sands or shale or coal — generally require more intensive use of energy and water. Quite apart from the carbon that’s emitted when these fuels are burned, the production process raises their greenhouse gas emissions – another factor that undermines our national security. Here is CNA’s Military Advisory Board again:

The link between oil consumption and global climate change is a key international security concern… Projected climate change is a serious threat to national security; it contributes to instability in some of the world’s most volatile regions and will increase tensions even in stable regions.

Will more North American oil production gives us stable supplies and prices? The Energy Information Administration predicts that oil production even from unconventional sources will begin to decline after 2020 — just seven years from now — as “sweet spots” disappear and the industry moves into “less productive or less profitable drilling areas.”

The result, as Christian Science Monitor columnist Kurt Cobb points out, is that unconventional oil won’t be cheap. He writes:

It’s unlikely to be plentiful either because unconventional oil will be challenging to produce at the same high rates we’ve been producing conventional oil… (W)e cannot count on it to provide as much energy to society as we are used to from much higher quality fuels…(This) flies in the face of the (wildly misleading) conventional wisdom about unconventional oil. But if we are to make intelligent policy and personal decisions about energy, we will be better prepared if we work with the available evidence rather than relying on the oil industry’s pronouncements of wonders yet to come.

The Keystone XL pipeline would be yet another financial investment in the fuels of the past at a time we need to quickly pivot away from them and toward cleaner forms of energy.

So, contrary to the views of Jack Gerard, Keystone XL would not signal that America is “serious about its energy future.” It would signal that we’re not. If we want energy that is plentiful, clean, sustainable over generations and a plus for national security, then we should be disinvesting in fossil energy and expediting our transition to renewable energy resources.

Can that transition happen overnight? Of course not. But if only because of climate change, it must happen much more quickly than any energy transition any industrial economy has made anytime in the past. To make it happen, we must fully commit to a new energy paradigm where, rather than digging, drilling and burning resources that make us less secure, we receive the inexhaustible and clean energy that’s available all around us.

Is such a transition realistic? Yes. There is an impressive body of credible research, some of it listed on the Presidential Climate Action Project website, showing that renewable energy could provide as much as 100 percent of our energy by mid-century.

Writing about this research, Elisabeth Rosenthal of The New York Times cited a study published in the journal Energy Policy on whether New York could meet all of its energy demand with wind, water and sunlight. She quotes the study’s principal author, Mark Z. Jacobson, a professor of civil and environmental engineering at Stanford:

It’s absolutely not true that we need natural gas, coal or oil — we think it’s a myth. You could power America with renewables from a technical and economic standpoint. The biggest obstacles are social and political — what you need is the will to do it.

As Rosenthal reports, 13 countries got more than 30 percent of their electricity from renewable resources in 2011, while only 9-12 percent of our power came from renewables in the United States. Overall, 56 percent of our energy still came from oil and coal. The fact that we’re considering more investment in those fuels, including the Keystone XL pipeline, says something unflattering about America’s intelligence and our commitment to true national security.

This is the first in a two-part post. Part 2 will look at President Obama’s latest “blueprint” for clean energy, and the ways it moves us backward rather than forward.