Serena Williams was the perpetrator, not the victim, of unprovoked abuse in last Saturday's U.S. Open final against Naomi Osaka.

Geopolitical tensions have spiked across the world. No arms control negotiations are currently under way to reduce global nuclear stockpiles.

Signing the treaty banning nuclear weapons would put Japan on the right side of history, geography, legality, morality and humanity.

Instead of trying to counterbalance China through a collective defense pact, the Quad four should build an informal security architecture.

Despite praise for last week's "unprecedented" summit, there were good reasons why previous U.S. administrations had refused multiple requests from North Korean leaders to meet.

U.S. National Security Adviser John Bolton detests professional diplomats as gutless appeasers, and has yet to meet an arms control agreement he likes or a crisis that cannot be solved by bombing the enemy.

The U.S. president's decision to pull out of the Iran nuclear deal will worsen ties with Europe, destabilize the Mideast and complicate efforts to reverse North Korea's nuclearization.

The belief that the Kim-Trump summit will produce a definitive resolution rests on irrational exuberance.

The pieces of the jigsaw are falling into place on the Korean Peninsula. But the overall picture — a denuclearized North Korea, a nuclear-weapon-free zone for all of Northeast Asia and a U.S. withdrawal from East Asia — remains fuzzy.

The Kim-Trump summit is an opportunity that will be difficult to seize and easy to squander.