Early Monday morning, after a long awaited summit between American President Donald Trump and North Korean Supreme Leader Kim Jong Un, the president announced that the U.S. will halt military exercises on the Korean peninsula. These military exercises date back years, and have long been touted as an integral component in developing interoperational capabilities between South Korean forces and American troops. North Korea, on the other hand, has long called them “rehearsals for invasion.”

“Under the circumstances that we’re negotiating a very comprehensive complete deal I think it’s inappropriate to have war games … It is something that (North Korea) very much appreciated,” President Trump said in a post-summit press conference.

“The war games are very expensive; we paid for a big majority of them, we fly in bombers from Guam,” Trump said. “That’s a long time for these big massive planes to be flying to South Korea to practice and then drop bombs all over the place and then go back to Guam. I know a lot about airplanes, it’s very expensive.”

While political pundits drew lines in the sand and began defending new fortified positions regarding if Trump “legitimized” Kim’s leadership by meeting with him or began the historic march toward peace, defense analysts looked at these comments and grew concerned for different reasons. National defense must be, by its very nature, approached pragmatically: to protect the nation and its interests, you must take the world as it is, not as it “ought to be.”

From a diplomatic standpoint, one can see why President Trump would use military exercises on the Korean peninsula as a bargaining chip in these negotiations, but the looming concern in the minds of those oriented toward threat deterrence rather than political theater remain: those drills were never meant as a nuclear deterrent — they were always a conventional one.

North and South Korean forces have, very literally, been staring one another down from across the militarized border for decades, since well before the Kim dynasty’s nuclear ambitions had come to fruition. Warfare on the Korean Peninsula, it’s long been known, doesn’t need to involve nukes to be incredibly costly in terms of human life — in fact, Kim could kill millions without sending a single soldier over the border.

North Korean artillery, perhaps more so than any other military asset, poses a direct threat to the South Korean capital city of Seoul. The city itself is well within range of Kim’s massive cannons, and intelligence agencies have long asserted that there may be a number of North Korean spies living within its urban sprawl. These spies don’t need to be James Bond-esque to turn the tide of a war with South Korea, they need only to provide accurate targeting coordinates to the artillery crews on the other side of the border to ensure the barrage arrives with deadly effect.

These artillery placements range from mobile assets to primitive tube launchers tucked away throughout the mountains overlooking the North/South border. The total number of them, their locations, and their fortifications are significant unknowns – we know they’re out there, we know there are many of them, but where and just how many remain a bit of a mystery for the most part.