North Korea's latest nuclear test has prompted global outrage and left world leaders scrambling to find a way to avoid a catastrophic war on the Korean Peninsula.
What are the U.S. diplomatic options on North Korea?
The Trump administration believes cutting off fuel supplies is the best way to curb Pyongyang's pursuit of nuclear arms.
Such sanctions are likely to be unacceptable to China, which supplies nearly all of North Korea's energy needs. Beijing fears an oil cutoff could topple the North Korean regime and make it vulnerable to a South Korean takeover, a scenario unacceptable to China. Chinese leaders want to preserve the regime in Pyongyang as a strategic buffer against U.S. influence in East Asia.
What are the U.S. economic options on North Korea?
President Donald Trump has said the United States could stop all trade with countries doing any business with North Korea. But besides China, North Korea has trade ties with close U.S. partners like Germany, India and Russia. Cutting trade ties with any or all of them would prove disastrous for U.S. business.
Other economic sanctions imposed by the United Nations, the United States and the European Union have failed to make an impact on Pyongyang.
What are the U.S. military options on North Korea?
There are three:
1. South Korean officials have indicated that they may consider bringing back U.S. nuclear weapons to the peninsula.
2. A pre-emptive strike could be conducted against North Korea's missiles and nuclear facilities.
3. A full-scale invasion could be undertaken.
If so challenged, the regime in Pyongyang could retaliate against South Korea or Japan. Even without a nuclear weapon, Pyongyang can inflict catastrophic damage on the South Korean capital, Seoul, home to more than 10 million people.
What if North Korea attacks?
The U.S. has a number of defenses in place, including the anti-missile defense system THAAD, which shoots down short-, medium- and intermediate-range ballistic missiles, and the ship-based Aegis system, which can track 100 missiles simultaneously and intercept them. It also has the Patriot missile defense system in Japan.
U.S. Defense Secretary Jim Mattis recently said, "Any threat to the United States or its territories, including Guam or our allies, will be met with a massive military response, a response both effective and overwhelming."