The U.S. recently deployed the Terminal High-Altitude Area Defense (THAAD) system to South Korea to buffer its defense against a possible North Korea missile attack. Indeed, Pyongyang’s aggressive ballistic missile testing and the possibility it is preparing for its justifies a robust response. But many questions persist about THAAD’s overall effectiveness.

First, a primer on THAAD is necessary. The system is based on a simple enough concept: “What if you could knock out a missile with another missile?” Which sounds simple enough, until you consider that these missiles are moving at many thousands of miles an hour, and you just go ahead and try hitting a bullet with another bullet.

Using massive, powerful radar systems like the trailer-based , the THAAD system is supposed to track short, medium, and intermediate-range ballistic missiles, similar to the ones North Korea would be theorized to use in a nuclear shooting match. In development since the 1990s, the THAAD system has been hitting short range targets since 2005, and actually managed to shoot down a simulated medium-range ballistic missile in 2012. But it hasn’t demonstrated a kill of an intermediate-range missile like , which can chuck a warhead more than 2,000 miles away.

And how the system would perform if it had to deal with multiple missile salvos, featuring dozens of warheads, all at once, as pointed out.

It has also evoked from residents in Seongju County, North Gyeongsang Province where it is located; THAAD is located on a , to be exact. Residents fear the missile defense system makes them a bullseye in the event of a North Korean attack and that THAAD is nothing more than a symbol of U.S. geopolitical interests that will leave South Koreans shouldering the bulk of any collateral damage.

And then there is the question of how well THAAD will perform in an actual attack. Like the Ground-based Midcourse Defense system (GMD) , THAAD has a spotty test record. Phillip Coyle, who has more than 30 years of government-level nuclear weapons testing experience and one of America’s top missile defense experts, wrote in that the system failed six tests in the 1990s.

Though it boasts an 11-for-11 success rate since 2006, those tests are heavily scripted to ensure THAAD succeeds, Coyle wrote. He also noted that system has not proven that it can adequately handle more than one missile attack at the same time:

In its , THAAD cooperated with Patriot and Aegis defense systems to down five ballistic and cruise missiles. Although this test was considered integrated, , and THAAD only intercepted one medium-range ballistic missile.

THAAD has not been independently tested against more than two ballistic missiles and was not designed to defend against cruise missiles.

Meanwhile, it is that North Korea has 1,000 ballistic missiles, between 10 and 16 nuclear weapons, and one of the largest arsenals of in the world. If Pyongyang attacked South Korea, the North, knowing that an American counter-attack was inevitable, would be incentivized to use all of its weapons. We don’t know whether THAAD can intercept three incoming missiles, let alone hundreds. And if these missiles carried chemical or nuclear weapons, even one missile that evaded the defense systems would cause catastrophic damage.

Then there is the issue with its radar. It can only cover 120 degrees at a time, a blind spot North Korea can easily exploit by launching a submarine-launched ballistic missile (SLBM) that can be fired from any location by covered by THAAD’s radar.

To put all of this context, THAAD has not proven it can handle, say, eight or nine missiles coming at it. (North Korea has ) If North Korea was serious about launching a ballistic missile attack at the south, do you really think Pyongyang will launch one missile and wait to see what happens?

Of course not.

China has never been a fan of the system, which is causing South Korea problems. Beijing is not concerned about the interceptor capabilities itself. Instead, its surveillance capabilities are the issue. As points out, the Chinese have reason to worry:

China’s right to believe that THAAD surveillance data could be transferred to other BMD assets protecting CONUS. Indeed, one of THAAD’s missions would be to strengthen U.S. defenses against the possibility of North Korean ballistic missile attack on CONUS. So it has to be able to transfer data to CONUS-based radars and interceptors. But the United States already has a THAAD battery deployed on Guam, two AN/TPY-2 radars deployed in Japan (at Shariki and Kyogamisaki), space-based assets, plus a range of ship-borne radars and larger land-based radars in other parts of the Pacific theatre. Would a THAAD deployment in South Korea change much? The short answer is that it could improve early tracking of some Chinese missiles, depending on their launch point. Still, that might not make actual interception of those missiles much easier. ICBM warheads move fast. And sophisticated penetration-aids help to confuse missile defenses.

In retaliation, Beijing has responded to THAAD by cutting off tourism from China to South Korea, which can cut the number Chinese tourists visiting the country by 70 percent; that can possibly turn into billions of dollars in tourism-related revenue, according to .

Suddenly, there visa issues with South Korean entertainment artists trying to perform in China and state TV encouraging a boycott of South Korean products, according to . It is unclear how the U.S. is supporting Seoul with the collateral impact of THAAD’s deployment.

While the system is a powerful symbol of America’s commitment to South Korea’s regions security, it is nothing more than a bandaid for a bigger problem—which is that Washington appears unwilling to talk to Pyongyang.

Then there’s the local resistance. On March 18th, some 5,000 people in the Seongju region protested THAAD’s deployment in their backyard. Many of the people, as observed, feel they are pawns for Washington’s geopolitical chess game in the region:

Yoon Geum-soon, a resident of Seongju and the former national chairperson of the Korean Women Peasants Association, says the fight against THAAD is a fight to end the U.S.’ hold over South Korea’s foreign policy:

For over 60 years, the so-called US-ROK alliance has been based on our subordination. As long as our country does not have the autonomy to pursue its own foreign policy, the regional conflict will only worsen and we will suffer for it. We have no choice but to end this cycle.

At the moment, THAAD is merely symbolic and will not make South Korea safe. It is technically subject to being and its spotty test record proves it is incapable of stopping a full-scale ballistic missile attack.

All THAAD is doing is making South Korea shoulder an even more tense geopolitical problem without the White House mapping out a concise plan of how to engage Pyongyang. So far, it seems like Washington’s only solution is the military, but , and it will do little to make South Korea safer. THAAD doesn’t either.

Despite more tough talk from the U.S. and allies, North Korea seems dead set on more missile tests…