Imagine this scenario: a lightly-armed US Navy intelligence-gathering ship cruising off the coast of North Korea is suddenly surrounded by enemy patrol vessels demanding that it surrender. Only a few kilometers away, a destroyer belonging to the Japanese Maritime Self Defense Force – the navy in everything but name –happens to be cruising close enough to offer help.

The prime minister must make a quick and agonizing decision. Does he order the destroyer to the rescue of a friendly vessel in harm’s way, thereby violating the constitution, breaking the law and possibly exposing the ship’s captain to criminal charges if any North Korean is killed? Or should he obey the law, restrain the captain and thereby almost certainly destroy the alliance with its main protector beyond repair?

This scenario is by no means far-fetched. A lightly-armed US Navy vessel, the USS Pueblo, was waylaid by the North Koreans and seized in January 1968. The only difference is that there were no Japanese naval vessels (nor American naval or air assets either) close enough to help the Pueblo when it was surrounded and captured.

Yet it is this kind of scenario that lies behind the renewed push to pass necessary changes to the Self-Defense Forces Act to permit it to engage in what’s called “collective self-defense.” Briefly, it refers to a country coming to the aid of an ally when it is under attack and the party is in a position to help out. For years the government has interpreted collective defense as going against the country’s war-renouncing constitution.

The US-Japan security arrangement is often called an “alliance.” It is not. The term alliance is purely a courtesy title. The so-called alliance is in essence a deal. The US promises to defend Japan if attacked, with nuclear weapons if necessary (the nuclear umbrella). In return, Japan agrees to permit American bases on its soil for Americans to use basically as they see fit.

However, Japan is not obliged to defend the US if she comes under attack. The most commonly mentioned scenario – intercepting a North Korean intercontinental ballistic missile fired over Japan on the way to the US mainland - is considered by most observers as far-fetched. The “Pueblo scenario,” rendering assistance to US Navy ships if needed, is a more likely contingency.

The main emphasis behind a push to approve collective defense is Japan’s rapidly expanding involvement in United Nations Peacekeeping Operations (usually rendered with the letters PKO). In the past 20 years, more than 8,000 Self Defense Force troops have been involved in PKOs in half a dozen countries. Engineering troops are currently stationed in South Sudan, army medical personnel help in earthquake-ravaged Haiti. The navy takes part in anti-piracy patrols in the Gulf of Aden.

The 2007 changes to the Self Defense Forces Act made participating in UN-approved peace operations one of the main missions but didn’t solve such issues as lending assistance to other nations participating in the joint operations. Japan cannot now come to the assistance, say, of an NGO targeted by terrorists, for example, or to a non-Japanese ship attacked by pirates based in Somalia.

“The SDF is literally crossing its fingers that nearby friendly units won’t come under attack” on missions, says Yuichi Hosoya, a law professor at Keio University. Other naval vessels on anti-piracy patrol avoid getting too close to Japanese vessels, he said. “It’s too dangerous.” That Japan has never been in a quandary over protecting is colleagues on anti-piracy patrol “has been sheer luck.”

Earlier Liberal Democratic Party administrations had sought to modify the current restrictions against collective defense, but were in office for too short a time to accomplish anything. Prime Minister Shinzo Abe’s recent remarks to the effect that he is no rush to enact the change probably comes from a realization that the current government, still enjoying 60 percent plus approval ratings after eight months in office, is in for a long stretch.

Currently, two special committees have been convened to consider aspects of Japan’s security posture looking forward. They are expected to make their recommendations later this year and introduce them in the Diet next year. One is the Advisory Panel on Reconstruction of the Legal Basis for Security, dealing with the collective defense issue. The other is the Advisory Panel on National Security and Defense Capabilities.

Additionally, the Diet will consider two security-related bills in the current special session that began this month. They include a law to create a National Security Council similar to the American NSC. Along with it is a projected doubling of the penalties for leaking classified information. Washington considers the current regulations too slack, obliging it to withhold certain sensitive information.

The panel on National Defense Capabilities is separate from the collective defense panel and looks into other issues such as the advisability of permitting pre-emptive strikes against a country (say North Korea) that it believes is preparing to launch a missile attack against Japan and the advisability of creating a Marine Corps-like branch of the ground forces to defend or if necessary retake Japanese islands south of Okinawa.

These could be considered offensive capabilities outlawed by Article 9 of the constitution. On the other hand, the Defense Ministry specifically defines proscribed offensive weapons systems as being Intercontinental Ballistic Missiles, long-range bombers and aircraft carriers. It does not mention cruise missiles, troops trained in amphibious assaults or aerial refueling aircraft.

Put this all together and it seems to herald significant shift toward a more militaristic Japan. That certainly is how many would interpret it. These measures would gut the war-renouncing Article 9, destabilize the regional security environment, irritate China and drag Japan into American-inspired conflicts that it has no desire to take part in.

Or, it may simply recognizing the changing security circumstances in northeast Asia, including North Korea’s obtaining nuclear weapons and China’s growing intransigence over the disputed Senkaku/Diaoyu islands. Speaking at the first session of the Defense Capabilities panel in September, Abe said: “I will proceed with the rebuilding of the national security policy that clearly addresses the realities facing Japan.”

The prospects of any of this being enacted are uncertain. The current relatively short Diet session is crammed with many potentially contentious issues mostly related to the government’s economic program. There may be opposition from the parliamentary coalition partner, the New Komeito, which is more pacifistic than the LDP. But at the moment the government has the luxury of time.