President Donald Trump says if North Korea attacks anyone the U.S. cares about, they should be nervous because ‘things will happen to them like they never thought possible.’ (Aug. 10)

The president has a long to-do list, starting with slowing down and changing his tone. He should emulate Churchill and Reagan, not Kim Jung Un.

North Korea’s nuclear weapons challenge is as serious a crisis an American president has faced since the end of the Cold War. That is why President Trump should tread carefully and wisely before hurtling us toward conflict in Asia.

Trump is right on the key threat. North Korea’s aim to develop a nuclear weapon that could hit the West Coast of the U.S. and Canada is unacceptable. We know enough about the criminal regime in Pyongyang to be clear about our own bottom line: We can’t allow it to blackmail our country for years to come.

Before the Trump administration decides to confront Pyongyang’s menacing young leader, Kim Jong Un, however, it should take time to deepen the U.S. strategic position on the Korean Peninsula for the struggle ahead.  

More: Shaky Trump team isn’t ready for North Korea nuclear crisis

More: No way to treat diplomats and security: Trump’s risky State Department moves

There is much Washington must now do. Trump should strengthen the U.S. military presence in South Korea and Japan to meet our defense commitments to both allies. He should continue to invest in missile defense systems to protect the U.S. homeland. He should enlist the political support of Australia, New Zealand, India, Singapore and others, including our NATO allies, to isolate North Korea as the instigator and threat to peace. 

Most important, Trump must continue to make North Korea the focal point of our relationship with China. President Xi Jinping has significant influence on Kim through Beijing’s food and energy exports to Pyongyang, but he is reluctant to use it. Trump can make it crystal clear to Xi that U.S.-China relations will sink or swim on this key issue. As the world’s two strongest countries, we should coalesce to manage this threat together. Should China not help us, Trump could retaliate with a potent but risky option — the imposition of American…