The killing of two Japanese taken hostage by the Islamic State group has savagely driven home the high stakes Japan faces and limited options it can muster in such circumstances.

Journalist Kenji Goto's beheading, seen in an online video over the weekend, also offers a glimpse into how Japan is struggling to handle the rising menace of terrorism.

Until this crisis, Japan had not become directly embroiled in the fight against the militants, who now control about a third of both Syria and neighboring Iraq in a self-declared caliphate. Tokyo's backing for U.S.-led air strikes against the Islamic State group is confined to financial and humanitarian aid for refugees and other non-military support for countries affected by the conflict.

That proved no hindrance for the jihadis.

"What we should realize is that the Japanese are no exception to terrorist targets. We really should open our eyes to see this reality," Kunihiko Miyake, a former diplomat and researcher at a private think tank in Tokyo, told a news show on TV Asahi.

"The levels of safety precautions Japan has taken up until now are not enough," he said. "We must review and step up security for Japanese, not only those abroad but here in Japan."

Japan's options for trying to free the hostages were limited. Tokyo lacks a strong diplomatic presence in the region and has a very small corps of Arab experts. Moreover, the military is confined by the constitution, drafted by U.S. occupying forces after World War II, to a strictly self-defense role and would be unable to stage a rescue attempt.

The video showing Goto's killing, purportedly from the Islamic State militants, carried chilling threats to single out Japanese anywhere as targets.

Addressing Prime Minister Shinzo Abe, a man resembling a militant shown in other beheading videos by the Islamic State group says, "because of your reckless decision to take part in an unwinnable war, this knife will not only slaughter Kenji, but will also carry on and cause carnage wherever your people are found. So let the nightmare for Japan begin."

Abe has made security a top priority of his administration. He ordered greater vigilance at airports and at Japanese facilities overseas, such as embassies and schools. The government already was considering sending troops for overseas rescues.

In parliament Monday, opposition lawmakers questioned Abe over his response to the crisis and challenged his desire to expand the scope of Japan's military.

Abe already has sought and won a reinterpretation of the constitution by his Cabinet allowing defense of an ally, such as the U.S., in limited conditions under a concept known as "collective self-defense."

The Jan. 20 ransom demand for Goto and for the other hostage, gun aficionado and adventurer Haruna Yukawa, came days after Abe, while visiting the Middle East, announced $200 million in humanitarian aid to nations fighting the militants. Since the ransom message addressed Abe and demanded the same amount for the hostages, some critics have faulted him for having directly mentioned the Islamic State group in announcing the aid.

"We should not be seen succumbing to terrorism, but there is no need for provocation. We should not send them the wrong message," said Yukio Edano, a former trade minister with the opposition Democrats.

Japan's aid may help discourage refugees from becoming recruits of the Islamic State group, but Abe should have used more caution, said Koichiro Tanaka, chief Middle East analyst at the Institute of Energy and Economics in Tokyo.

Abe rejects those misgivings and says he took the hostages' plight into account when making his speech.

"I thought announcing Japan's contribution to fulfill its responsibility would contribute to the international community's effort to fight terrorism and prevent its expansion," he told parliament.

Nationalists in Japan might try to use the hostage crisis as a pretext for a stronger military, said Stephen Nagy, a professor of politics at International Christian University in Tokyo.

But he notes that the U.S. has lost several citizens to the Islamic State group over the past months "and has been incapable of rescuing them. And they have apparently the most sophisticated military in the world and experience in such rescues."

For Japan, and possibly the rest of Asia, a more urgent issue is the possibility Islamic State extremists may be more likely to target their citizens, using them as pawns in Middle East regional politics, Nagy says.

Japan's handling of the hostage crisis was complicated by the odd series of messages purportedly from the Islamic State militants. The intertwining of Goto's predicament with the plight of a Jordanian pilot captured after his F-16 fighter jet crashed near the Islamic State's de facto capital Raqqa in December added a further layer of complexity.

The standoff appeared to be mostly a waiting game: dependent on Jordan as a go-between, the Japanese side had no direct communications with the extremists, government spokesman Yoshihide Suga told reporters.

"It was just one-sided propaganda," Suga said.

Many Japanese seemed less angry than stunned, and in some cases terrified, by the brutality of the killings.

So the hostage crisis and other events like the recent terrorist attacks in Paris, may well convince the public that it's safest not to push things too far, said Michael Cucek, an adjunct fellow at the Institute of Contemporary Asian Studies at Temple University in Tokyo.

Since its defeat in World War II, Japan has tended to follow the lead of its powerful ally, the U.S., in global affairs. Some Japanese chafe at that and support Abe's attempts to project a stronger Japan to counter China's rise, but many embrace the constitution's anti-war stance and oppose changes that might raise tensions with Japan's neighbors.

Public opinion polls last week showed no shift in views about such issues, Cucek said.

"So we have no evidence of a post-9/11 like hysteria igniting public demand for greater activism and fewer restraints on government action, the ends of greater security justifying the means," he said.

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