Sixty-four years after North Korea and the United States signed an armistice to suspend the Korean War, the U.S. State Department has forbidden American citizens from traveling to the hermit state. The notice was put in the federal register on August 2; it becomes effective on Friday.

Tourists walk on the Broken Bridge that divides North Korea and China, April 1, 2017. REUTERS/Damir Sagolj

The travel ban is a relatively easy picking amongst a platter of bad choices for President Donald Trump. The U.S. president has not yet elaborated on his warning to North Korea that “all options are on the table” after Pyongyang fired a missile over Japan on Tuesday, but something like the travel curb could be a small sign of what is to come.

The restriction on visits to North Korea came about because over the last decade it has for various reasons detained around 15 U.S. citizens, all of whom have become bargaining chips and leverage for Pyongyang in its dealings with Washington. It’s a pattern that forces U.S. officials to expend resources, time and political capital to try to secure the release of these Americans.

Most tragically, in July Pyongyang returned one detainee – Michigan college student Otto Warmbier – in a coma. His death a few days later gave impetus to the State Department’s push for a travel ban. Separate from this initiative and before Warmbier’s death, a bipartisan-sponsored bill to stop Americans traveling to North Korea began wending its way through Congress. It is not clear yet what that will end up including or how this State Department ban will affect that legislation.

But what will the travel ban accomplish? Washington has three main goals: to prevent American visitors being used as bargaining chips by Pyongyang, to deny the regime tourist dollars and to send a message about the unacceptability of Pyongyang’s behavior.

The first goal will be partially achieved. The ban immediately eliminates the risk of any one of the up to 1,000 Americans who visit each year on a tourist visa from falling afoul of the authorities.

On closer inspection, however, it appears as if only four of the 15 to 17 Americans that have been detained since 2009 were tourists. (Different sources have different numbers on Americans detained.) Several cases involved individuals who crossed the China-North Korea border illegally for religious or journalistic reasons. Others held were Americans conducting humanitarian, development, health or education work in the country.

The State Department has made clear that U.S. citizens visiting for “limited humanitarian or other purposes may apply to the Department of State for a special validation passport.” Perversely, such people may now be more vulnerable: if Pyongyang is looking for political pawns, there will be a smaller pool to choose from.

Still, the need for a special passport may allow the U.S. government to vet who can travel to North Korea for work. Many humanitarians or educators focused on North Korea appear to have deep religious convictions that make them vulnerable to breaking some of the country’s rules, written or unwritten. The ability to deny a “special validation passport” may allow the State Department to protect some of these people from themselves.

There are currently three Americans detained in Pyongyang: Kim Hak-song, Kim Sang-duk and Kim Dong Chul. They were all detained in separate incidents: Kim Dong Chul had projects in the Rason Special Economic Zone and was accused of espionage; Kim Hak-Song was leaving a teaching post at an evangelical Christian-funded university in Pyongyang, the Pyongyang University of Science and Technology. Kim Sang-duk was doing the same 18 months later. The latter two were both stopped at the airport as they were about to fly out and accused of engaging in “hostile acts.”

In the end, a travel ban will probably reduce the number of detainees the United States has to deal with, but it is unlikely to eliminate them altogether.

The second and third goals are more closely related. The roughly 1,000 U.S. tourists a year indeed do contribute to the growing North Korean economy. However, the average Western tourist spends around $2,000 per trip, so their impact is small. Even if all tourism stopped tomorrow – including from China –and Pyongyang lost out on the roughly $30 million this industry provides its nuclear and missile programs would be unaffected.

Nor do profits from tourism go into some central regime coffer. The major misunderstanding about North Korea today is the assumption that it is a command economy, with everything done by and for the state. In fact, it is largely a market economy with multitudes of companies connected to different institutions, paying individual wages, buying input materials from suppliers, and when possible even hiding earnings from the authorities. Tourist dollars get spread around to some extent.

That isn’t to say that tourists can entirely avoid supporting Kim Jong Un’s goals. When visitors fly into the country on Air Koryo – as most do – they are paying money to a military-owned company. And that military is, of course, now dedicated to developing weapons that can hit the U.S. mainland. After the State Department announced in late July it would seek a travel ban, several North Korean missile tests and multiple rounds of rhetoric were launched across the Pacific Ocean. Pyongyang, fond of symbolism, referred to “the powerful nuclear hammer” it could inflict “at the heart of the U.S.” if it thought Washington was trying to oust Kim.

This travel ban is also a form of symbolism. In a real sense, it is a statement that North Korea’s behavior is so far outside acceptable norms that the U.S. government is willing to forbid its own citizens from traveling there. It also signals U.S. intent to clamp down on North Korea’s economy, even in small ways.

There will be costs, too. Person-to-person exchanges can influence how people think, even in a controlled state like North Korea. Exposure to foreign people and ideas has changed how Pyongyang middle and upper-middle class residents see the world. Observers of North Korea also learn a surprising amount from the tourism industry, as tourists frequently spot changes and trends in-country. Some of this will be lost if the tourist industry contracts.

The ban is an exceptionally rare action for the United States. It will go down as one more marker in the long history of conflict between the United States and North Korea. It is sobering to think that the men who signed the armistice in 1953 are long gone, while this tortured relationship endures.