Japan, America’s closest ally in Asia, has been raising the alarm over Taiwanin recent days. Last week, a new white paper from the Defense Ministry called for “stabilizing the situation surrounding Taiwan” given that the geopolitical climate has “a sense of crisis more than ever before”. This echoes comments made by the Japanese Deputy Prime Minister Taro Aso last week who noted that a “major incident” over Taiwan would be viewed as a direct threat to his country’s security. These headlines are a reminder about why the U.S. policy of strategic ambiguity—which has helped avoid a crisis—remains valuable today.