Before U.S. President Donald Trump starts celebrating the apparent diplomatic rapprochement on the Korean Peninsula, he should consider the challenges that lie ahead.

A dangerous world could become more dangerous still.

The complexity of the Syria situation has far surpassed the world's ability to master it.

South Korea's president has both neutralized the threat of North Korean disruption to the Olympic Games and kept a thin-skinned U.S. president firmly on his side.

Trump has used his first year in office to reverse America's traditional role as a guarantor of security and democratic values.

Almost one year into his presidency, Trump's only achievement regarding North Korea has been to secure additional sanctions from the United Nations.

The U.N. is far from perfect. But, rather than bash it, U.S. leaders should understand that its actions and decisions are often an extension of their own.

The challenge in North Korea is not just a nuclear crisis. It is a crisis of the quality of U.S. leadership.

The idea that North Korea will abandon its weapons programs in exchange for the promise of security and regime survival has been tested has failed whenever it has been tested.

Only by connecting the strategic dots between Afghanistan, Syria and North Korea can the world find a somewhat coherent, but misguided, approach to U.S. foreign policy.