There is a growing consensus in the government that Japan cannot continue treating East Asia simply as a vast industrial estate for Japanese corporations. Last month a panel commissioned by Mr Miyazawa to examine relations with Asia called for Japan to 'play a considerably greater political role and to make a greater contribution than in the past'.
With the ending of the Cold War, no one in Tokyo is quite sure what this role should be. Mr Miyazawa is to visit Indonesia, Malaysia, Thailand and Brunei; he is planning an important policy speech in Bangkok this week.
The most intractable problem for Japan in dealing with East Asia in general is the growing risk of military confrontation. China and all the South-east Asian states are building up military power as rapidly as their economies are expanding. Arms sales are booming in the region. At the same time the US, which has acted as a guarantor of regional peace up to now, has withdrawn its forces from the Philippines and is planning a gradual reduction of its remaining troops in Korea and Japan.
But, as Masashi Nishihara, a professor of international relations at Japan's National Defence Academy, points out, Japan is in no position to replace the US. 'Could we change our function and be like the US sending marines into Somalia? Could Japanese forces, even under UN auspices, use force overseas agressively? Would other Asian countries come to us and ask for our forces? I think not.' At most, he says, Japan can try to use economic leverage over Asian nations to slow the arms race. 'I would hope that Mr Miyazawa might hint that Japanese ODA (official development assistance) might be conditional on arms acquisition.'
Already the country's dilemma is coming to the surface in Cambodia. After two years of debate, Japan's parliament finally voted to dispatch troops as part of the UN peace-keeping mission to Cambodia last October. This was seen as the first step towards an expanded, benign role for Japan in Asian affairs. But by law the troops must withdraw from any outbreak of hostilities, and as the Cambodian peace plan begins to unravel officials in Tokyo are considering an early pullback of the 600 troops in Cambodia.
Last week the Foreign Minister, Michio Watanabe, caused a minor diplomatic storm by suggesting that Japanese troops should be allowed greater freedom to act as international peace-keepers.
'From now on, the role of the Self-Defence Forces should be to maintain global peace and order under the leadership of the United Nations,' said Mr Watanabe, adding that the military should have more long-range aircraft and ships to do so. This sent a shiver around Asia, and advisers said this was just Mr Watanabe's opinion, not government policy.
During Mr Miyazawa's Asian tour, Cambodia is likely to be high on the agenda. Tokyo is also keen for a greater dialogue on security issues with the six member states of the Association of South East Asian Nations (Asean) - Thailand, Malaysia, Singapore, Indonesia, Brunei and the Philippines.
While trade negotiators argue at the Gatt talks that Japan cannot drop its ban on rice imports, the Agriculture Ministry is quietly arranging for a consignment to be imported because the domestic harvest cannot meet demand.
Officially, rice cannot be imported because Japan must maintain self-sufficiency for national security reasons. But despite huge subsidies to farmers the annual yield is going down, because rice- farming is losing its appeal.