The Strategic Petroleum Reserve, an emergency petroleum store maintained by the Department of Energy, contains approximately 700 million barrels of crude oil, for which America paid a mere $17 billion for the oil and $5 billion for facilities. Much of the oil was purchased years ago, and today it is worth about $90 billion. Financially, the reserve has been one of the federal government’s better investments.

Recently, Congress voted to stop filling the reserve with expensive oil. It is tempting to say we should go further and actually sell the oil in the reserve and reap the profit. This approach, so the speculation goes, would not only generate receipts for the Treasury, but would also expand domestic supply, thereby at least temporarily reducing domestic prices for crude. But selling this reserve, or even drawing it down, would be an ill-advised policy.

Investing in oil and oil futures is not a uniquely governmental activity. Quite the opposite: Thousands of companies and countless individual traders do their part to arbitrage the price of oil to represent every possible market contingency. One of the scapegoats for the current price of oil is a group called “speculators,” as if these individuals were separable from and even hostile to the efficient workings of the market. In a world where each of us may choose to fill up our tank today as opposed to tomorrow, we are all speculators.

The federal government, though one of the largest owners of crude oil, did not fill its reserve for speculative purposes. The original impetus was to combat hostile international supply disruptions, not price perturbations. America has experienced two instances of such prolonged disruptions, World War II and the 1973-74 Arab oil embargo. Both led to higher petroleum prices, exacerbated further by ill-conceived government rationing programs.

In the 1970s the federal government began development of its reserve in subterranean salt domes along the Louisiana coast. In the past 30 years, the reserve has been tapped only twice when prices spiked: during the 1991 Gulf War, when oil prices were in the $24 a barrel range, and in the immediate aftermath of Hurricane Katrina in 2005, when prices approached $60 a barrel. Of course, prices today are above $130 a barrel.

Congress has wanted to tap the reserve for any number of reasons. In 1996, when oil prices were only $20 a barrel, both Congress and the Clinton administration seriously considered a large sale of petroleum from the Weeks Island reserve, as that facility needed to be shut down for technical reasons. Congressional interest at that time focused on balancing the budget.

We have a reserve not for the political whim of Congress but to protect us in the event of a major supply disruption. We are as vulnerable as ever, with nearly two-thirds of our crude oil imported from elsewhere. Although Canada and Mexico are two of our largest suppliers, much of our oil comes from lands with governments either unstable or hostile to our own. We have a petroleum reserve neither to hedge oil prices nor to balance our budget or to lower prices temporarily before an election. We have the reserve because a real oil supply disruption would have calamitous costs.

We reasonably complain that, even without supply disruptions, crude oil prices are twice those of a year ago and four times those of four years ago. We can buy as much oil as we want; we just can no longer afford it.

During the 1973-74 embargo, prices spiked fourfold in a matter of weeks. With few options and no experience with embargoes, our government made a bad situation worse. Supplies were limited and prices were suppressed, ensuring that supplies remained short. If we had the reserve then, hostile countries might not have contemplated an embargo. Even if an embargo had ensued, its effect would have been substantially mitigated.

Recently, members of Congress agitated to release parts of the reserve to relieve temporarily high fuel prices. Yet it is difficult for the small amount of reserve oil to affect world prices. Oil is purchased anywhere, at great expense, for transport to America. Tapping the reserve would not meaningfully change the world price of oil, and certainly not for long. But tapping the reserve would make the world less safe for us and for our children.

A former FCC commissioner, Mr. Furchtgott-Roth is president of Furchtgott-Roth Economic Enterprises. He can be reached at hfr@furchtgott-roth.com.