A 19-gun salute will boom out across Peking's vast Square of Heavenly Peace here when Japanese Prime Minister Yasuhiro Nakasone begins his state visit to China today.
Mr. Nakasone is the first visiting dignitary to be so honored in 18 years, although he will not get the 21 guns reserved for President Reagan next month. Nakasone will meet China's top leaders - senior leader Deng Xiaoping, Premier Zhao Ziyang, and General Secretary Hu Yaobang.
Another sign of the out-of-the-ordinary welcome being prepared for the Japanese prime minister is an invitation to dine en famille with Mr. Hu.
Mr. and Mrs. Nakasone invited Mr. Hu to dine privately with them during the latter's very successful visit to Japan last November.
Now Mr. Hu wants to return the favor by hosting an intimate dinner for the Nakasones, their son and daughter-in-law.
The hosts will be Mr. and Mrs. Hu, their children and a granddaughter. No top Chinese leader has ever invited a state guest into his own home before.
In a world marked by turbulent change, China and Japan find themselves in the happy position of having no major outstanding problems between them. Mr. Nakasone's visit is intended to ensure that the two countries remain steadfast friends into the 21st century and beyond.
For much of the past hundred years, China and Japan have been enemies. China's oldest living generation remembers the humiliation of Japan's 21 demands during World War I. The next generation suffered the invasion of Manchuria in 1931.
Only those under age 40 have no personal memories of Japan's bombing raids or of its occupation of much of China during World War II.
The present halcyon mood between capitalist Japan and communist China is the result partly of Japan's abandonment of militarism and its rebirth as a democratic nation after World War II, and partly of the decision made by China's present leaders to modernize their country through an open-door policy of cooperation with the West. Japan has been the chief beneficiary of this policy. Sino - Japanese trade last year reached $10 billion and accounted for one-fourth of China's external trade that year.
During the past five years Japan has supplied China economic aid totaling $1. 87 billion, plus $2 billion dollars in export-import bank credits.
Mr. Nakasone brings to China a new, seven-year aid package totaling $2.14 billion for seven specific projects, mostly in transportation and natural resources. He will also discuss, but probably not finalize, a $3 billion export-import bank credit.
Tokyo will also grant Peking $22.32 million as a gift for telecommunications training equipment and for a meat-processing research institute.
On the political side, Mr. Nakasone is most interested in promoting a dialogue between North and South Korea aimed at defusing tension on the strategic peninsula.
China shares this interest, but associates itself with North Korea's January call for a tripartite discussion between North and South and the United States. Japan, like Washington, wishes China to take part in the discussions and make it a foursome. Recently North Korea has shown signs of greater flexibility, while China has shown increasing cordiality toward South Korea. One Chinese source states flatly that China will attend both the Asian games of l986 and the Olympics of l988 to be held in Seoul.
Nevertheless, for the Chinese, the process of bringing the two Koreas together is a delicate and sensitive matter. One false step could drive North Korea into Moscow's waiting arms.
Mr. Hu is expected to visit Marshal Kim Il Sung in Pyongyang in May, by which time not only Nakasone but Reagan will have visited with the Chinese leadership.
Whether Hu will take some proposals and whether something positive will emerge from his talks remains uncertain.
Unlike Sino-American relations, Tokyo's ties with Peking do not suffer from the incubus of the Taiwan problem.
Through his visit to China, Nakasone hopes to strengthen and deepen the sense of shared interests between Tokyo and Peking.
China's backing for Japan, in turn, could provide essential underpinning for the leading role the Japanese prime minister wants his country to play, not only on the world economic scene as heretofore, but in the political realm as well.