This week Japan took a historic step. The Associated Press reported, “Since Japan’s defeat in World War II, its military has been shackled by restrictions imposed by a victorious U.S. and that, over time, a majority of Japanese adopted as their own. Now, the shackles are being loosened. Japan’s Cabinet on Tuesday approved a reinterpretation of the country’s pacifist postwar constitution that will allow the military to help defend allies and others ‘in a close relationship’ with Japan under what is known as ‘collective self-defense.’ ” Something has plainly changed in Japan’s neighborhood: “Previous governments have said the war-renouncing Article 9 of the constitution limited the use of force to defending Japan. Prime Minister Shinzo Abe said the shift is needed to protect the lives of the Japanese people in an increasingly severe security environment. Japanese warships would be able to help protect U.S. ships that were defending Japan, he said.”

Japanese Prime Minister Shinzo Abe speaks during a news conference in Tokyo on July 1. (Kazuhiro Nogi/Agence France-Presse via Getty Images)

Michael O’Hanlon of the Brookings Institution explains, “It only really applies to their being able to help defend us better in joint operations near their territories, or in UN missions where other countries might participate too and come under threat, and the Japanese might be in a position to help defend them.”

That said, when a country changes 70 years of established policy, it is worth looking at why. Daniel Blumenthal of the American Enterprise Institute e-mails me: “We needed and wanted a real mutual defense treaty where they could also defend us. We faced a twisted circumstance in which if a missile was headed our way from North Korea, officially Japan could not participate in shooting it down.” It’s nevertheless reflective of the risks our allies now face. “That is the good news, Japan is doing what we have urged it to for years. The bad news is that there is no doubt that Japan is losing confidence in us,” he explains. “They are beside themselves on the ‘red line’ issue in Syria [and] on the Russia situation. And on China treating us with contempt.”

It is evident that like every other adversary, China doesn’t much respect, let alone fear, the United States. Blumenthal notes that “a few days after Obama left Asia and despite all these warnings from [Defense Secretary Chuck] Hagel and [Secretary of State John] Kerry to settle territorial disputes peacefully, China dropped [an] oil rig in maritime territory disputed with Vietnam.” In essence, we’re urging Abe to “continue his bold leadership, even more remarkable since we are not showing any.”

It is a positive sign when our allies accept shared responsibility for their defense. But, as Blumenthal puts it, “we do not want a crisis of confidence in the alliance.” It is noteworthy that this is occurring at the same time our allies in the Middle East are acting in ways not helpful to the United States (e.g. backing radicals in Syria and Iraq) because they no longer trust U.S. leadership. Israel may be forced to go it alone militarily against Iran because it cannot rely on a U.S.-brokered deal to disarm Iran and does not take seriously the threat of U.S. action (neither does Tehran).

Japan has been a stalwart post-World War II ally, and the administration appropriately welcomed its constitutional reinterpretation. But it should also listen to Japan, our other Asian allies, Eastern European powers, Middle Eastern Sunni monarchs and the array of nervous allies around the globe. They are expressing near-unanimous concern about U.S. reliability, staying power and willingness to assert itself. One need only look at the raging civil war in Syria, the near-collapse of Iraq, the Russian aggression in Ukraine and China’s territorial overreach to see why.

Jennifer Rubin writes the Right Turn blog for The Post, offering reported opinion from a conservative perspective.