In Japan, a new prime minister has been confronted with a new security challenge on his country's doorstep: a North Korea that has formally demonstrated its ability to explode a nuclear weapon. Last month's nuclear test has intensified a debate about whether Japan should develop its own nuclear bomb. In a Financial Times interview, Shinzo Abe said that he would strive during his term to amend the constitutional article that constrains Japan from developing its military forces.
In Germany, meanwhile, the cabinet of chancellor Angela Merkel endorsed a white paper approving an expansion of the international role of the country's armed forces. The policy document, the first on the subject in 12 years, pointed to radical changes in the country's security environment - such as the growth of terrorism and the spread of weapons of mass destruction - "that are not only having a destabilising effect on Germany's immediate surroundings but also impact on the security of the international community as a whole". It said an effective military was "vital to a German security and defence policy that seeks to actively shape its environment".
The developments may give pause for thought given the destruction that the aggressive military traditions in both nations caused in the 20th century. But although China and surrounding countries will be watching Japan closely, Germany's neighbours are likely to welcome the development. So does the US, which wants both countries to assume a greater share of a global security burden of which it feels it carries a disproportionate part.
Neither shift presages a step-change of military posture: they reflect gradual changes under way since both made their first postwar deployments of troops overseas as part of a United Nations peacekeeping operation in Cambodia in 1992.
Yet the announcements do show that both countries are becoming more open to debates about national interests that have been thwarted or taboo for years.
The historical parallels are unmistakable. Both operate under constitutions drawn up by Americans or under heavy US influence - and, after imposing basic laws that sought to end both countries' militaristic traditions for ever, the US spent much of the rest of the century cajoling them both into expanding their armed forces.
In both countries, the anti-militaristic tradition is more than a matter of law: lessons from the second world war have been absorbed by many in the population. In contrast to the US, they share deep scepticism about the efficacy of military power in solving international disputes.
In both, the strategic shift heralded by the end of the cold war has at last been matched by a generational shift. Mr Abe, who took office in September, and Ms Merkel, who this month celebrates a year in power, are the first leaders of their countries to be born after the war ended.
Yet the differences between them exceed the similarities. Germany is embedded in multinational alliances: the European Union and Nato. It is surrounded by friendly countries and has no obvious adversary. On the other hand, Japan's only bulwark against hostile or suspicious neighbours is its bilateral alliance with the US.
"They are completely different cases," says Volker Rühe, Germany's defence minister from 1992 to 1998. During the cold war, in contrast to Japan, Germany could mobilise large numbers of troops quickly: a force of 1.3m could be mustered at seven days' notice.
Neighbours such as Denmark and the Netherlands are urging Germany to expand its military budget, something those of Japan are hardly likely to do. Moreover, having first deployed forces in Cambodia along with Japan, Germany has sent its troops overseas in many more operations.
Yet North Korea's nuclear test has added more urgency to the debate in Japan. The main ostensible obstacle to a more assertive military posture has been article nine of its 1947 "peace constitution". In it, "the Japanese people forever renounce war as a sovereign right of the nation and the threat or use of force as means of settling international disputes". The section continues: "In order to accomplish the aim of the preceding paragraph, land, sea, and air forces, as well as other war potential, will never be maintained. The right of belligerency of the state will not be recognised."
In his FT interview, Mr Abe said the provision no longer suited the times. "I believe this article needs to be revised from the viewpoint of defending Japan, and also in order to comply with the international expectation that Japan make international contributions," he added. He said he would strive to achieve a revision.
The article has been interpreted since the 1950s as allowing Japan to maintain self-defence forces, but not as a means for settling international disputes. Apart from that, other principles have been adopted over time that do not always have the force of law but would require political capital to overturn. They include a principle, first enunciated in 1976 and breached only once in 1986, that Japan's defence spending should not exceed 1 per cent of gross national product, and a repeated public pledge that Japan will not become "a military great power".
They also include the so-called three nuclear principles: that Japan will not produce, possess or introduce nuclear weapons. The third of these principles may have been breached by allowing US ships carrying nuclear weapons into Japanese ports.
Yet, though it is widely understood to have the technical capability to develop an independent nuclear deterrent quickly if it wanted to, Japan has preferred to rely on the US nuclear umbrella, a commitment that Washington was quick to re-emphasise last month after the North Korean test.
The test has, however, opened up the nuclear debate, though Christopher Hughes of Warwick University's Centre for the Study of Regionalisation and Globalisation says this subject is for now more of an issue among the media than among the Japanese public or policymakers. On conventional forces, Mr Abe's views do not represent a revolution, he says. In the early to mid-1990s, Japan began to expand its security concerns from its own territory into the Asian region. Since the attacks on the US of September 11 2001, it has been pulled by Washington towards a more global role.
Its contributions remain modest, however, and its troops operate under highly restrictive rules of engagement. According to latest UN figures it provides just 31 troops - in the Golan Heights - out of a total 77,000 in UN peacekeeping missions around the world. Its 600 soldiers managed to spend two years with the US-led coalition in Iraq without firing a shot.
Meanwhile, the debate about how to extend Japan's role overseas has not penetrated significantly into a society that remains, Mr Hughes says, deeply anti-militaristic.
Yet a bigger overseas profile for Japan looks inevitable. While Japan could in theory either go it alone or take a multilateral route, he says, it will almost inevitably become further enmeshed with the US, despite a long-standing resistance to "entrapment" by Washington. This entanglement can only grow as, for example, Japan buys into the US missile defence system. Moreover, the North Korean challenge will force Tokyo into detailed discussions with Washington over nitty-gritty operational questions, such as war planning, that it has hitherto resisted.
For Germany, the strategic issues are less stark. Germany has already done significantly more: it has more than 9,000 troops in multinational engagements abroad, including 3,200 in Afghanistan, 2,850 in Kosovo, more than 1,000 in Lebanon, 875 in Bosnia and 750 in Congo. It is also contributing a naval force to support the UN mission in Lebanon. It spends more than Japan relative to its economy - 1.4 per cent of gross domestic product in 2004 - though less than Britain (2.3 per cent) or France (2.6 per cent).
Legal restrictions against a wider role for the military are also much weaker. Article 87a of the 1949 constitution, or basic law, states simply: "The Federation shall establish Armed Forces for purposes of defence." But, according to Bastian Giegerich of the International Institute for Strategic Studies in London, the notion that this prevented Germany's armed forces from operating outside the country was a political interpretation rather than an actual legal constraint.
In July 1994, the federal constitutional court finally removed the perceived legal obstacles to German forces operating "out of area". Participation in international missions was in line with the basic law, it said, so long as it took place within a collective security framework - meaning supporting bodies such as the UN, Nato and the EU.
The new white paper calls for an expansion of forces that could be regularly deployed abroad from 9,000 now to 14,000. The 250,000-strong military would be split into three elements: a 35,000-member response force capable of relatively high-intensity missions; a stabilisation force of 70,000 from which would be drawn troops for lower intensity peacekeeping operations; and a support force of 147,500.
Much in the paper formally recognises changes that have already taken place. But it also provides a public strategic rationale for the extension of German forces overseas, citing for example terrorism and the spread of weapons of mass destruction. It also cites economic reasoning: "Germany, whose economic prosperity depends on access to raw materials, goods and ideas, has an elementary interest in peaceful competition of thoughts and views, an open world trade system and unrestricted transportation routes." This explicit depiction of German interests - commonplace in a country such as Britain, France or the US - is unusual in Germany, says Mr Giegerich.
Yet, while the government has formally concluded that Germany needs to shake off some of its postwar reticence and project its armed forces overseas, public support for the idea appears fragile. "I don't know that there is a broad constituency in the country for this," says Jeff Gedmin, director of the Aspen Institute Berlin.
This is true, for example, of the mission in Afghanistan where there was widespread public revulsion at newspaper pictures of German troops desecrating a human skull. Mr Gedmin describes public support for this operation as "thin" and thinks it could be easily reversed by events there.
Mr Giegerich agrees: "The understanding is that this is a reconstruction mission: people are not supposed to die and they are not supposed to kill anybody either. If that reality changes, that means the German government would have a fairly significant domestic problem on its hands in terms of support for the mission."
Shaky public support means that the government is nervous about deploying its troops in Afghanistan, based mainly in the relatively safe north of the country, to help Nato allies such as Britain and Canada in the much more dangerous south. It also means German troops operate under severe restrictions on what they can do operationally.
Mr Rühe says the failure of the government to prepare Germans for their troops to undertake a tougher combat role in Afghanistan betrays "a lack of leadership". It also weakens Germany in the eyes of its Nato allies, he says.
It emphasises also that further extending the reach and effectiveness of Germany's armed forces will be fraught with domestic political difficulties - as will efforts to persuade the anti-militaristic population of Japan that it needs a more assertive military.
The sloughing off of the inhibitions that emerged from the second world war are often said to be signs that Japan and Germany are becoming more "normal" countries. But the road to full "normality" appears unlikely to be smooth.