There are some very detailed writeups of PRNK's ability to damage Seoul based on open sources around on the web. The short summary is that 'flatten in a few moments' may be an exaggeration, but they do present a very real and very large threat.
They do have a fair number of dug in artillery installations that could survive several airstrikes. The basic template of these installations are bunkers under mountaintops that artillery can move rapidly in and out of. So instead of shoot and scoot more like shoot and turtle up. They may have limited resources, but the PRNK does appear to know how to deploy them quite effectively. Chemical shelling is a particular concern.
It's not that the PRNK would win an outright war, it's that they could extract a massacre no one else wants.
They do have a fair number of dug in artillery installations that could survive several airstrikes. The basic template of these installations are bunkers under mountaintops that artillery can move rapidly in and out of. So instead of shoot and scoot more like shoot and turtle up. They may have limited resources, but the PRNK does appear to know how to deploy them quite effectively. Chemical shelling is a particular concern.
It's not that the PRNK would win an outright war, it's that they could extract a massacre no one else wants.