For North Korea, sanctions are safer than a strike, experts say

President Trump warned Tuesday that if China doesn’t solve the “North Korean problem,” the United States will do it alone.

The context is dramatic: A U.S. aircraft carrier group has been rerouted toward the Korean Peninsula days after a U.S. missile strike in Syria, and North Korea responded to Trump’s message with threats of a nuclear strike on the U.S. mainland in case of any U.S. aggression.

But experts say the most likely U.S. response to North Korea's belligerence is not a military one but an economic one: dramatically tightened sanctions that strangle the isolated nation's economy more than ever before. Here is how it would work:

The U.S. Treasury should bar companies that use the U.S. financial system from doing any business with North Korea or with companies in other countries that do, said Bruce Bechtol, a political science professor at Angelo State University in Texas and an expert on North Korea.

North Korea’s nuclear program and weapons sales represent 40% of the nation’s economy, which would be shut down with “sanctions that go after non-North Korean entities that support their financial networks,” Bechtol said. “If Americans pull out, so does Canada, the European Union, China, Singapore and all the rest.”

Trump threatens to deal with North Korea if China won't help

Such an effort would require the U.S. Treasury to issue a rolling list of sanctioned businesses that finance North Korea, mainly small banks in China, Singapore, Vietnam and Hong Kong.

A financial dragnet would cover all foreign intermediaries working on North Korea’s behalf, including banks involved in money laundering, front companies that North Korean agents open and close frequently and foreign individuals who establish bank accounts for the use of North Korean agents in return for financial kickbacks, Bechtol said.

“That would bring North Korea to its knees,” he said.

Past sanctions targeted North Korean companies and individuals involved directly in supporting the country’s nuclear and missile programs, and major exports, such as coal, that produced cash for those programs. A more comprehensive approach would shut down other sources of income and threaten the regime led by strongman Kim Jong Un, Bechtol said.

If the financial noose is tight enough, the regime “could implode,” he said.

George Lopez, who served on the United Nations Panel of Experts monitoring sanctions on North Korea in 2010-11, said the goal of comprehensive sanctions would be to “get them (North Korea) to the bargaining table.”

Scott Snyder, a senior fellow at the Council on Foreign Relations, said he’s not sure there’s time even for comprehensive sanctions to prevent the North from developing a nuclear weapon delivery system that could reach the U.S. mainland.

“There’s a greater sense of urgency and time is not on the U.S. side,” Snyder said. “That drives the options toward the extremes, negotiations (or) capitulation or the use of military force.”

And if North Korea falters under sanctions, China is likely to come to its neighbor's aid as it has in the past, Snyder said.

“If North Korea started to show signs of real duress in terms of refugees, I think the first thing the Chinese would do is turn on the humanitarian spigot to prevent regime change,” he said.

Part of the reason is that North Korea serves as a buffer between China and U.S. forces in South Korea, and the collapse of the regime could send millions of refugees fleeing into China.

“North Korea lives in a space that exists in the strategic mistrust between the U.S. and China,” Snyder said. "That gap will remain as long as the U.S. wants a unified Korean Peninsula under Seoul," the capital of South Korea. Plus, he added, "China does not want a unified Korea allied with the U.S.”

Despite Trump’s tough talk, a military option is not realistic, Lopez said. While no U.S. leader wants to be vulnerable to an erratic leader like Kim, a military strike is dangerous as well, he said.

It would require targeting the North’s nuclear development sites, as well as thousands of artillery batteries which are poised to rain destruction across South Korea and Seoul, where millions live. “It would be all out war,” he said.