The beheading of two Japanese citizens by Islamic State militants is fanning calls to allow Japan's long-constrained military to conduct overseas rescue missions as part of Prime Minister Shinzo Abe's push for a more muscular security posture.
Even some advocates of legal changes to make rescues possible, however, say Japan's military faces big hurdles to acquiring the capacity to conduct such missions, while critics say sending troops overseas would just increase the risk.
Islamic State militants said on Sunday they had beheaded a second Japanese hostage, war reporter Kenji Goto, prompting Abe to vow to step up humanitarian aid to the group's opponents in the Middle East and bring the killers to justice.
In a video of the purported killing, a knife-wielding militant addresses Abe and says the knife will not only slay Goto but also "cause carnage wherever your people are found".
Abe wants to legislate this year to lift a ban on the military fighting overseas to help allies under attack. Known as collective self-defence, the change would be the biggest military policy shift since Japan's armed forces were reassembled 60 years ago after its World War Two defeat.
Other proposed changes would also widen the scope for military participation in rescuing citizens abroad.
"The point is the need for a legal system so that we can protect our citizens properly," former defence minister Yuriko Koike said. "With this incident, such cases have increased and I think the debate will become more substantive."
Koike said in an interview that even if Japan had the legal structure, it would not be able to launch a rescue like Israel's bold 1976 anti-terrorist commando operation at Uganda's Entebbe airport.
"But if we are not prepared, we have no choice," she said, adding preparations would be a deterrent against terrorist acts.
An internal briefing paper for top government officials, seen by Reuters last week, said cases like the Islamic State crisis did not meet proposed conditions for Japan to send troops to join allies in combat. It dodged the question of whether planned legal changes would allow rescue missions in such cases, but a Japanese defense official said it would not.
The official added that even if legal changes were made, Japan lacked the military capability and necessary intelligence network to mount such missions.
"Before we discuss whether it is possible legally, we should discuss whether it is possible in terms of capability," he said.
After 10 Japanese hostages were killed by Islamic militants at a gas complex in Algeria in 2013, Japan revised a law to allow its military to travel over land to bring freed hostages home from overseas. Previously, Japan's pacifist legal limits meant they could only go as far as air or sea ports.
Now some want to go further.
"I believe we need to go ahead and discuss the matter," ruling Liberal Democratic Party Secretary General Sadakazu Tanigaki said in a TV debate on Sunday.
"There are voices questioning whether it is alright to just rely on the foreign country concerned or whether we don't need to do anything, even if that country has asked us for cooperation," he added.
In a sweeping cabinet resolution last July, the government said it wanted to expand the scope for military rescues as "police activity", but only when Japan got agreement from the relevant country's government and that government had control of the area in question. The government hopes to enact laws to implement such changes in a parliamentary session now underway.
The intelligence gap has already led to calls for Japan to beef up its overseas spy network. "It's time Japan discusses ... the creation of a government agency to gather overseas information," said Shigefumi Matsuzawa, secretary general of the small, right-leaning Party for Future Generations.
On the other side of the political fence, caution reigned.
"The Self-Defense Forces should never be dispatched (overseas). That would only bring about a chain reaction of acts of terrorism and hatred," said Seiji Mataichi, secretary general of the tiny Social Democratic Party.
The hostage crisis emerged after Abe pledged during a Middle East tour to provide $200 million in non-military aid to countries contending with Islamic State. It could give Abe a bounce in support as the public rallies against what the premier condemned as an "utterly cruel and despicable act of terrorism".
Abe is likely to try to use the crisis to help push his conservative agenda which includes eventually revising the U.S.-drafted, pacifist constitution.
"It (rescue missions) is not realistic. But they will use it as an entry point to push the debate on collective self-defence more broadly," said Sophia University professor Koichi Nakano.
Abe will also face tough questions over whether his policies are making Japan safer or putting its people at greater risk, experts said, although the opposition was weak and divided.
"Right now, Abe will benefit from a 'rally round the flag' response," said Jeffrey Kingston, director of Asian Studies at Temple University's Japan campus.
"But over time, people will ask hard questions," he added.