Japan’s 1947 constitution, which was written in just one week by US occupation officials after the Second World War, has never been touched. One reason is that it is especially complex to make any amendments -- not only does the parliament have to give its OK, but a two-thirds majority is needed in both houses of the Japanese Diet.

Kerstin Lukner, an expert in Japanese foreign policy at the University of Duisberg, explained that a referendum was also necessary: "50 percent of Japanese have to agree on the new constitution."

By approving a bill outlining the procedures for a referendum, Japan’s parliament has now laid the groundwork for amending the country's pacifist constitution. Critics say that changes could raise concerns in neighbouring countries, which remain suspicious of Japan because of its military history.

Japanese want to remain pacifist

But strong opposition will also come from within Japan, because most Japanese still want the country to remain officially pacifist, said Lukner. "Most people don’t really agree with sending the Self-Defence Forces, for example, to Afghanistan or to Iraq," she said.

"If you look at the opinion polls maybe 50 percent, but not there are not many more who really agree with these detachments. Most Japanese people really care, and are paying great attention to the on-going discussion on changing the constitution."

The Self-Defence Forces Law of 1954 banned Japan from any offensive military action and ensured that civilians would control the armed forces. The result was a unique defence system, which was also one of the best-funded in the world.

Greater global role

But Prime minister Shinzo Abe, the first to be born after the Second World War, wants Japan to have a full-fledged military so that the country can assume a greater global role. This would include more participation in peacekeeping operations overseas, and co-operation with the United States in the so-called "war on terror".

"What the prime minister wants to do is change the constitution, so the Self-Defence Forces can participate in collective self-defence measures," explained Lukner. "Right now what is allowed is only individual self-defence -- If Japan is attacked the Self-Defence Forces can react."

Up until now, each time it has wanted to deploy the "Self-Defence-Forces" abroad, the government has had to re-interpret Article 9 of the constitution, which renounces Japan's right to wage war.

Not for today

The bill approved on Monday says a referendum could only take place after 2010. Japan’s ruling Liberal Democratic Party is already working on a new draft constitution, but would have to seek approval from all Japan's political parties in order to actually change it.

So that means that although a major step has been taken this week, it will still take some time until the land of the rising sun sees a new constitution.