This report discusses the rapid advancements North Korea has made in its nuclear weapons and ballistic missile programs since 2012. Despite the absence of any missile launch activity or nuclear tests in 2018 to date, previous tests and official North Korean statements suggest that North Korea is striving to build a credible regional nuclear warfighting capability that might evade regional ballistic missile defenses. Such an approach likely reinforces their deterrent and coercive diplomacy strategy--lending more credibility as it demonstrates capability--but it also raises serious questions about crisis stability and escalation control. Congress may further examine these advances' possible effects on U.S. policy.