Krauthammer lamented that nothing really has been done for over 25 years on the issue of North Korea. He said the United States' options were to return tactical nukes to Korea, which we withdrew in 1992, and to encourage Japan to go nuclear. Krauthammer basically said those options were risky and fraught with danger.
Instead, he suggests the United States just acquiesce to what North Korea is doing like we did when China went nuclear. I guess we should not expect Trump to follow up his threats.