On July 1, the cabinet of Prime Minister Shinzo Abe announced an evolution in Japan’s military doctrine. The government has reinterpreted the restrictions governing Japan’s use of force in international disputes. The new decision reverses the postwar understanding that the constitution completely forbids Tokyo from defending its allies from attack.

The change is highly controversial. The move’s critics feel Abe is pushing Japan to remilitarize after nearly 70 years of peace.

On the day of the announcement, 10,000 protestors gathered outside the prime minister’s official residence. Smaller demonstrations sprang up across the country—but the most disturbing of these had happened days earlier.

On June 29, an elderly man climbed onto the girders supporting a walkway above Shinjuku station, the world’s busiest train terminal. Wearing a suit and carrying a megaphone, he sat cross-legged and discussed his plans to commit suicide. He continued his vocal protest of the government’s impending decision for an hour.

He then poured gasoline all over his body and immolated himself in front of the shocked crowd. Emergency workers attempting to coax him down quickly stamped out the fire and rushed the man to hospital. The suicidal protester is in a critical condition. Social media coverage of his actions shocked the nation.

What would drive a man to attempt suicide protesting a right that every other country considers reasonable? The answer lies in the fear that Japan might relive its tragic wartime past.

It is important to understand what the government’s announcement really means. Under the new interpretation, Tokyo can intervene to help close allies—namely, the United States—when an attack “threatens Japan’s survival and poses a clear danger to fundamentally overturn people’s right to life, liberty and pursuit of happiness.”

The previous interpretation only allowed for the minimum use of force in response to direct attacks against Japan.

Since the postwar constitution came into law in 1947, its ninth article has strictly limited Japan’s defense policies. The pacifistic statement declares that “the Japanese people forever renounce war as a sovereign right of the nation and the threat or use of force as means of settling international disputes.”

The new interpretation uses other sections of the document to balance the strict anti-force message of Article 9.

The government’s announcement focuses on the preamble which codifies Japan’s desire to live in “an international society striving for the preservation of peace, and the banishment of tyranny and slavery, oppression and intolerance for all time from the earth.”

It also draws from Article 13 in its requirement that the government protect its citizens’ “right to life, liberty and the pursuit of happiness.”

International law permits collective self-defense, but a 1972 interpretation of the constitutional limits on force deemed it legally off-limits to Tokyo. This is where the nationalist prime minister’s interpretation breaks with tradition.

The reinterpretation allows for “a minimum required level of force to protect Japanese citizens” when an attack on a foreign country “threatens Japan’s survival.”

Still, critics are unhappy.

Left-wing opponents of the move have criticized this new focus for “watering down” Article 9, labeling it a move away from Japan’s postwar anti-war values. Many are unhappy that the prime minister has not chosen to seek formal constitutional reform.

Abe’s reasons are obvious.

Constitutional reform requires a two-thirds majority in both the upper and lower houses of the Diet plus a majority in a national referendum. The ruling Liberal Democratic Party holds 61 percent of the lower house and only 47 percent of the upper house. It would be unlikely to pass a reform motion through the Diet—and even if it did, polls suggest a close fight if the government put reforms to a national vote.

Critics also ask why Japan needs to loosen its constraints on collective self-defense. Many still hold that continued, or even increased and more neutral, non-violence is Japan’s best choice. The recovering militarist nation has legally ruled out its ability to aid an ally for the last 67 years—why should that change now?

For Abe, the answer would incorporate the rise of China, Japan’s international security commitments and the need for greater alliance burden-sharing with the United States. But the government’s inability to explain this to the public has frustrated supporters of collective self-defense.