An independent U.S. think tank says North Korea is regarded as one of the largest plausible threats the U.S. must prepare for next year.

The U.S. Council on Foreign Relations listed a severe North Korean crisis in its report “Preventive Priorities Survey: 2012.” The report categorizes possible contingencies into three tiers based on their relative urgency and importance to U.S. nation interests.

The report rated North Korea as a “Tier 1” threat, warning against political instability and military provocations from the communist country.

Other “Tier 1” contingencies include a mass casualty attack on the U.S. homeland or its allies, a major military incident with China, and an Iranian nuclear crisis.