New York (CNN Business) America's new role as the world's leading oil producer made it easier for President Donald Trump to crack down on Venezuela and Iran with punishing sanctions.

But don't be fooled. The United States can't rely solely on domestic oil. To prevent price spikes, Washington still needs OPEC producers to fill the gap during times of stress.

"Shale is not superman," said Helima Croft, RBC Capital's global head of commodity strategy.

Tellingly, the White House announcement last month on Trump's Iran crackdown emphasized a commitment from Saudi Arabia and the United Arab Emirates. Those two OPEC nations, the administration said, pledged to "take timely action" to meet global oil demand as Iranian exports vanish.

"The fact that Trump has to call Saudi Arabia shows the limits of American energy dominance," said Croft, a former CIA analyst.

Texas tops Iraq

The shale boom is being tested by the latest geopolitical chaos

In January, the Trump administration intensified pressure on Venezuelan President Nicolas Maduro by imposing sanctions on PDVSA, the nation's state oil company.

Venezuela was long a leading oil supplier to the United States. But not anymore. US oil imports from Venezuela have vanished because of the sanctions, widespread power outages and years of under-investment.

Despite rising oil prices, Trump vowed last month to zero out Iran's crude exports.

To reassure markets, Trump officials pointed to America's skyrocketing oil production. US output has more than doubled from about 5 million barrels per day in early 2009 to nearly 12 million today, according to the US Energy Information Administration.

"We are much less dependent on foreign oil than we were before," said Jason Bordoff, a Columbia University professor and former energy adviser to President Barack Obama.

Texas alone has pumped more oil than Iraq, OPEC's No. 2 producer, for six months in a row, according to S&P Global Platts. Powered by the surging Permian Basin in West Texas, the Lone Star state has doubled its oil output in six years to a record 4.9 million barrels in December.

"I can't imagine the US would have taken the same approach towards Iran and Venezuela had it not been for the oil boom," said Meghan O'Sullivan, who served as a national security adviser to President George W. Bush.

Net energy exporter by 2020

US crude oil exports have spiked since Congress lifted the 40-year ban on foreign sales in 2015.

The shale boom isn't just about oil though. Fracking has left the United States with an abundance of natural gas as well. Today, much of that cheap gas gets shipped overseas in the form of liquefied natural gas.

In fact, the United States is expected to become a net energy exporter next year for the first time since 1953.

And that has powerful geopolitical consequences.

For instance, the European Union, seeking to reduce its dependence on Russia, has ramped up its natural gas imports from the United States.

Still reliant on Saudi Arabia

One challenge to the US strategy of energy dominance is the fact that not all oil is the same. The decades-old US refinery system was designed to run on low-quality, heavy crude. That's the kind of crude found overseas in places like Saudi Arabia, Venezuela and Iran. US shale, on the other hand, is much lighter.

If US refineries don't have enough heavy crude, they could struggle to produce the amount of gasoline, jet fuel and diesel required to run the American economy.

"Shale's shoulders cannot handle multiple producer crises," said RBC's Croft.

And it's still a global market.

"If there is a supply disruption anywhere, oil prices go up everywhere, including the United States," said Bordoff.

O'Sullivan, the former Bush official who is now the director of Harvard University's Geopolitics of Energy Project, said the shale boom doesn't mean the United States is no longer invested in the stability of Middle East nations like Saudi Arabia, Iran and Iraq.

"The reality is that as large producers, these nations have a very significant impact to the global market — and we are tied to the global market," O'Sullivan said. "We are still linked to those geopolitical fortunes."

Saudi Arabia in particular finds itself in the driver's seat.

It remains the only major oil producer with the spare capacity to quickly bring more oil to the market during times of stress. US officials want Saudi Arabia to deploy some of that flexibility to keep oil prices from rising further.

"We still do depend on that spare capacity to stabilize markets in a way that shale cannot substitute for," said Bordoff.