Bryan Clark, a senior fellow at the Center for Strategic and Budgetary Assessments, was more direct.
“Most of our systems are not hardened against EMP. Some older analog or Cold War-era systems are,” Clark told The National Interest.
“It is unclear whether a high atmospheric nuclear explosion would cause a significant EMP effect at lower altitudes and whether North Korea could execute such an attack without also affecting their own capabilities.”
Mark Gunzinger, an air power analyst at the Center for Strategic and Budgetary Assessments and a former Boeing B-52 strategic bomber pilot, told The National Interest that the Pentagon been expect such asymmetric threats, but needs funding to address the challenge.
“Over the last decade, DoD [Department of Defense] has expressed its growing concern with ‘hybrid’ threats posed by potential aggressors with a mix of conventional, unconventional, and asymmetric capabilities including WMD [Weapons of Mass Destruction],” Gunzinger said.
“This will require funding to upgrade DoD's forces and weapon systems, including capabilities that can operate in WMD environments.”
On the specific issue of North Korea, Gunzinger said that an EMP would impact Pyongyang’s force too—but conceded that U.S. forces are probably more vulnerable to such effects.
“It is likely that NOKO's use of a relatively unsophisticated EMP weapon over the Korean Peninsula would affect their own forces and possibly their battlespace command and control infrastructure,” Gunzinger said.
Asked directly if U.S forces—which rely heavily on networks and advanced sensors are likely to suffer more—Gunzinger said that was a distinct possibility.
“Quite possibly, yes. Just didn't want to get into it too deeply,” Gunzinger said.
“It could have a crippling effect on military systems and networks that aren't appropriately hardened. Let's not forget the impact it could have on our allies...”