BEIJING, July 1 -- The Japanese government on Tuesday ratified reinterpretation of the country's pacifist constitution to allow exercise of the collective self-defense right, a move marking the most significant shift in its post-war security policy.

What is collective self-defense right?

The collective self-defense right is authorized, along with individual self-defense, by Article 51 of the United Nations Charter.

The article stipulates that if a country in the international system has suffered an armed attack, then any other country has the right, but not the duty, to use armed force against the aggressor in reliance upon the principle of collective self-defense.

Alliances normally suppose that allies have mutual responsibility to defend each other. The Japanese government considers Japan's participation in alliances to be constitutional, but not the military defence of its allies.

Why Japan was banned on exercising the right?

The 1947 war-renouncing constitution of Japan forbids the use of force as a means of settling international disputes and also prohibits Japan from maintaining an army, navy or air force.

After the end of World War II in 1945, Japan, who started the war and invaded a number of Asian countries, was requested to process the demilitarization under the supervision of the United States.

The resolution adopted by the Japanese cabinet sets three new conditions that would enable the exercise of the collective self-defense right, such as when there are "clear dangers" to the lives of its people and their rights due to armed attacks on Japan or "countries with close ties."

It will enable Japan to take military action to defend other countries even though the nation itself is not under attack, leaving the war-renouncing Article 9 of the country's constitution scrapped.

Why Japanese citizens oppose lifting the ban?

Exercising the collective self-defense right has triggered concerns both at home and overseas, as Japan, under hawkish Prime Minister Shinzo Abe's administration, is running fast on a right-leaning trail featured by denial of wartime atrocities and thirst for military glory.

The Japanese public, still haunted by war past, is concerned that the right to collective self-defense would open the door for Japan to join battles on foreign soil.

According to the latest survey conducted through June 27 to 29 by Japan's Nikkei News, half of Japanese oppose dropping the ban on exercising collective self-defense as the right may drag Japan into war. Only 29 percent of the respondents support the move.

Other countries in the region are worried that Abe is manipulating the right as a stepping stone toward Japan's military rebuilding, which would further complicates regional relations.