The escalating battle of nerves between Japan and China over a disputed island chain has focused the international spotlight on Shinzo Abe, Japan's pugnaciously conservative prime minister, who is carrying the heavy responsibility of war and peace on his hunched shoulders.

As east Asia's leading nations talk tensely of war and peace, Abe's critics say it is his brand of unrepentant, rightwing nationalism that has helped push the region to the brink. His supporters say Abe is rightly, finally standing up for Japan.

How Abe might react if China's unilaterally imposed "air defence zone" over the Senkaku islands in the East China Sea triggers armed clashes is a serious international concern. The US is pledged to come to Japan's aid should it be attacked, while hardliners in China's military leadership would welcome a fight over what they call "core interests". There is potential for a head-on superpower collision.

Since taking office as prime minister for the second time a year ago, stocky, tousle-haired Abe, 59, has avoided hotheaded actions and kept his political powder dry. But he is no patsy, either. Nobody knows for sure which way he may jump, if push comes to shove.

"Abe is very rightwing by traditional measures," said Akio Takahara, professor of international relations and law at Tokyo University, which makes him a potentially dangerous figure. "He is a historical revisionist at heart … He is a nationalist [pursuing] his 'new nationalism'."

In this sense, Takahara suggested, Abe was a throwback to Japan's past, and thus an obstacle to the sort of calm dialogue needed in dealing with China.

Not so, said Yoshiji Nogami, a former Japanese ambassador to Britain who has known Abe personally for many years. "He is, first and foremost, a politician and a politician's instinct is to survive. As his first premiership ended in such a disastrous way, he is determined to stay this time.

China's threats over the disputed Senkaku islands have served Shinzo Abe well, analysts believe. Photograph: Kyodo/Reuters

"In order to stay in power for a long period of time, I believe he can be flexible. He is not an ideologue. He is certainly a conservative, a nationalist and right of centre, but he is not an ideological rightwinger," Nogami said.

The research director of a leading Tokyo thinktank offered a third perspective: "I would call him one of a new kind of very conservative, patriotic politicians who are not always happy with postwar Japan's traditional, leftwing internationalists and their strong tendency towards irresponsible pacifism."

In short, he said, Abe was saying it was time for Japan to stand up for itself, that it was "OK to be proud" again.

Dangerous militarist or modernising reformer, Abe's career has rarely lacked controversy. Born in September 1954 to an affluent and influential family, he became Japan's youngest-ever prime minister in 2006 and the first to be born after the end of the second world war.

Abe's late father, Shintaro Abe, was foreign minister and his grandfather, Nobusuke Kishi, served as prime minister in the 1950s. Kishi was also a cabinet member during the war and was once suspected of war crimes by the allied forces. The case was thrown out.

Elected to parliament in 1993, Abe was later selected to work for the popular prime minister Junichiro Koizumi. He gained public notice by taking a tough stance on North Korean abductions of Japanese citizens and took a big political risk when he travelled to meet the North Korean dictator Kim Jong-il in 2002.

Abe's old-fashioned, some would say regressive, views on social issues began to take shape when he helped sponsor an education bill initially entitled Love for One's Country. He became deeply involved in the incendiary issue of how Japanese school textbooks talk about recent history, favouring a more benign, sanitised view of imperial Japan's past actions.

In 2006 he published what became a patriotic bestseller, Towards a Beautiful Country, which was viewed as his personal testament. Abe argued that "class-A" war criminals charged by the Tokyo tribunal after the 1945 capitulation were not criminals under domestic law.

From early on, Abe the alpha-male traditionalist appears to have had a woman problem. He frequently became embroiled in rows about the so-called wartime Korean comfort women, who were prostituted by Japanese troops, claiming at one point that coercion was not involved. His remarks caused outrage in South Korea and elsewhere.

"He's passionate about Japanese victims of North Korea – and blind to Japan's own war crimes," complained the Washington Post in a 2007 editorial.

In October last year Abe courted more region-wide controversy by visiting the Yasukuni shrine in Tokyo, which commemorates Japan's war dead (including some convicted war criminals). He has not visited again since taking office, but has suggested he would like to do so.

His continuing interest in reinterpreting article 9 of Japan's pacifist constitution, to allow the country to develop its military might unchecked, is seen as similarly inflammatory by the Chinese and Koreans, and further proof of his revisionist views. So, too, is his creation of a Restoration of Sovereignty Day, an annual event to mark the end of the American occupation.

Abe would doubtless like to suggest that, like Japan, he has changed as time has passed. His first term, 2006-7, was marred by Liberal Democratic party scandals, including a ministerial suicide, leading to his forced resignation on health grounds. This time around, he has eschewed social policy controversies and moved cannily to broaden his base support while pursuing a radical economic plan and an ambitious foreign policy agenda.

Shinzo Abe bows to Emperor Akihito and Empress Michiko during a national memorial service for the victims of the 2011 earthquake and tsunami. Photograph: Reuters

At home, his main focus is on economic recovery upon which, he argues, the success of Japan's other aspirations depend. Labelled "Abenomics", his approach comprises the three arrows: monetary easing, fiscal stimulus, and structural reform. In the short term, at least, the policy has boosted economic activity and GDP growth and produced a big lift in the financial markets, enabling Abe to declare in Washington: "Japan is back." The yen is down, inflation is up, and share prices have risen by roughly two-thirds. Growth of 4% in the first half of 2013 easily out-distanced other G7 economies. Predictably, economists in recession-hit Europe and the US have suggested they follow Japan's example.

A little modesty might be in order, Nogami said. "Abe will face a series of difficult issues in coming months, including the negative impact of the planned consumption tax increase and the failure of what we are calling the 'spring offensive' to raise wages …

"Third, there are the nuclear power plants.

"Next July some of the plants are due to restart. There is a strong anti-nuclear sentiment in Japan [following the 2011 Fukushima disaster] but in view of the overall energy mix, those plants are needed. How he can manage this divisive issue definitely affects his tenure."

For the time being, Abe looks secure. Twelve months in, with the economy improving and his LDP in firm control of both houses of parliament, he remains unusually popular in a country where prime ministers have come and gone with startling rapidity in recent years. "An opinion poll taken on 3-4 November showed Shinzo's approval rating at 68.5% with very few negative views on his personality. The silent majority's support for Shinzo is still there and it's real," the Tokyo research analyst said.

Abe's initial success in boosting Japan's economic fortunes after decades in the doldrums, and the enormous damage caused by the 2011 earthquake and tsunami, has proven a necessary precondition for advancing his autonomous global agenda. It also underpins his ambition to strengthen political, military and economic alliances with south-east Asia, Australia and India while reinforcing treaty ties with Washington.

In a speech to the UN general assembly in September, Abe vowed to make a revitalised Japan "a force for peace and stability" in the world, while putting China on notice that coercion would not work. China's threats over the Senkakus, its leadership's continued snubbing of Abe and Beijing's longstanding tendency to whip up anti-Japanese, nationalist sentiment to distract attention from domestic problems had served Abe well, in terms of propelling him into power and keeping him there, analysts and officials said.

Abe has also skilfully exploited the China problem to woo less-powerful neighbours. Since taking office Abe has visited all 10 members of the Association of South-East Asian Nations (Asean), an unprecedented piece of outreach by a Japanese leader. Last weekend he hosted an Asean summit in Tokyo marking 40 years of diplomatic ties.

In a classic soft-power exercise that totally outflanked Beijing, Abe ordered the biggest overseas deployment of Japanese armed forces since 1945, backed by generous donations, to assist the Philippines after last month's super-typhoon disaster.

He scored another, personal triumph when he flew to Buenos Aires in September and, Blair-like, helped to secure the 2020 Olympic Games for Tokyo.

Abe's expansive agenda, part of his attempt to reassert Japan's leading role in the world, includes strong emphasis on supporting women's rights – an apparent attempt to fix his "woman problem". About 40% of his UN speech was devoted to the subject. He wanted to produce a "society in which women shine" in Japan, he said.

"Japan respects the activities of UN Women and intends to become one of its leading contributors and thus an exemplary country," he said.

Scarred by his first experience as prime minister, Abe seems determined to stick to a cautious line, avoid repeating past mistakes and stay the course to 2015. Economic recovery remains his top priority.

But for a man of strong and passionate views, this restraint seems unnatural and may not be sustainable. International tensions may yet stir his blood and force his hand. Just how long he can – and wants to – keep a lid on the confrontation with Beijing, as China inexorably ups the ante, is east Asia's big unanswered question of 2014.

Potted profile

Born: 21 September 1954 (age 59), Nagato, Yamaguchi prefecture, Japan. He later moved to Tokyo.

Education: Seikei elementary school and Seikei high school, Tokyo. He studied political science at Seikei University, graduating in 1977and later at the University of Southern California's school of public policy, Los Angeles.

Career: Abe began work for Kobe Steel in 1979.

In 1982, he left Kobe and held a succession of government positions, including executive assistant to the foreign minister, Shintaro Abe, his father. He moved from there to work for the ruling Liberal Democratic party, and subsequently for the LDP prime minister, Junichiro Koizumi.

In 1993, he was elected as an MP for the Yamaguchi prefecture.

In 1999, he became director of the social affairs division and deputy chief cabinet secretary in the Yoshiro Mori and Junichiro Koizumi cabinets from 2000 to 2003.

In 2002, as chief government negotiator on the issue of Japanese citizens abducted by North Korea, he accompanied Koizumi on a surprise visit to meet the late North Korean dictator Kim Jong-il in Pyongyang.

In 2003, Abe was appointed secretary general of the Liberal Democratic party.

In 2006, Koizumi was forced to stand down (due to term limits) and was succeeded as prime minister and LDP leader by Abe.

In 2007, after a series of scandals, the LDP lost its majority in the upper house, and Abe announced that he was resigning on grounds of ill health.

In 2012, apparently fully recovered, he was re-elected LDP leader. Later that year, he was elected prime minister for a second time.

What they say: "Abe is one of a new kind of very conservative, patriotic politicians who are not always happy with postwar Japan's traditional, leftwing internationalists and their strong tendency towards irresponsible pacifism." – research director of a leading Tokyo thinktank.