“I think that we, the government, must confront this reality head on,” he said, explaining why the review was needed.

Pointing to growing tensions due to China’s increasing assertiveness and North Korea’s nuclear threat, Abe called for a review of a decades-old interpretation of the constitution that has banned Japan from exercising its right of collective self-defence, that is deploying its military to aid friendly countries under attack.

A lifting of the ban would be welcome to Japan’s ally the United States, but the proposal drew criticism from China, whose ties with Tokyo have been strained by a territorial row and the legacy of Japan’s past aggression.

“We’ve noted that Prime Minister Abe has taken a series of unprecedented actions in the areas of military and security, which leads us to believe that Japan, as far as history is concerned, has started on a negative path,” said Chinese Foreign Ministry spokeswoman Hua Chunying, a spokeswoman for China’s foreign ministry.

Southeast Asian countries embroiled in territorial rows with Beijing in the South China Sea could take a different view.

“The Japanese military can somewhat bring ‘balance’ to the region that is now under a ‘threat” from a rising and increasingly aggressive Chinese,” said Benedict Exconde of the Yuchengco Centre of the De La Salle University in Manila.

“Countries in Asia, especially those whose citizens suffered from the horrors brought about by the Imperial Japanese Army during the second world war such as South Korea and the Philippines, should not worry about this move by Japan because the country has long veered away from its imperialist past and is drifting more toward being an active regional power that maintains close partnerships with its friends,” he added.

Abe also said Japan should strengthen its ability to respond to so-called “grey zone” incidents – low intensity conflicts that fall short of a full-scale attack. Concerns about such clashes have increased due to the tense feud between China and Japan over tiny disputed islands in the East China Sea.

But Abe said the government would not adopt a recommendation by his private advisers that Japan also lift its ban on taking part in UN-led collective security operations, in which nations join together to propel an aggressor against one state.

In their report issued earlier, Abe’s advisers urged sweeping changes in a security policy long based on the principle that Japan has the right to defend itself with the minimum force necessary, but that combat abroad exceeds the limit imposed by the constitution’s pacifist Article 9.

“Don’t destroy the constitution”

Critics say the proposed changes would gut Article 9 and are a stealth attack on the constitution that would skirt formal amendment procedures that would be tougher politically. Protestors against the proposed change lined the street near Abe’s office, shouting “Don’t destroy the constitution.”

The constitution has never been formally revised since its adoption in 1947, although successive governments have stretched its limits, which if taken litreally ban the maintenance of any armed forces at all.

Abe, who took office for a rare second term in 2012, has made clear his desire to loosen the limits of the US-drafted charter long considered overly restrictive by conservatives.

Abe’s handpicked advisers said Japan’s increasingly tough security environment meant the nation could not defend itself fully under the current interpretation of the constitution.

“We have reached a situation in which we cannot sufficiently maintain our country’s peace and security or realise peace and prosperity of the region and international society under the current interpretation of the constitution,” report said.

Abe said if the review concluded a new interpretation of the constitution was needed, he would like to embody the change in a cabinet resolution followed by revisions to relevant laws.

But doubts remain about how far and how quickly Abe can proceed. His Liberal Democratic Party’s junior partner, the New Komeito, is wary, some in the LDP are also cautious, voters are divided and the LDP’s deputy leader is worried about the impact on local polls this year and next.

Critics say even small changes would open the door to more drastic moves later. “Considering the nature of collective self-defence, to say it would be ‘limited’ is impossible,” said Kyouji Yanagisawa, a former defence official who worked for Abe during his first 2006-2007 term as premier.

The advisers cited examples of actions Japan should be able to take. Among them were protecting a US warship under attack in waters near Japan; mine-sweeping in sea-lanes in a conflict zone; and intercepting a ballistic missile headed for America.

They also recommended legal changes to allow action in other cases where the military has been constrained by legal concerns, such as rescuing Japanese overseas and using weapons in UN peace-keeping operations.