A lot of water has flowed through Sasebo Harbor in southern Japan since the nuclear-powered aircraft carrier USS Enterprise last docked there. On its last visit in 1968, at the height of anti-American sentiment over the Vietnam war, thousands of left-wing demonstrators tried to storm the US Navy base against a barrage of tear gas, high-powered water cannons, and flailing riot police sticks. Almost 600 people were injured in repeated street clashes.
When the 75,000-ton, 4,800-man Enterprise sailed into Sasebo on Monday, it was ringed by Coast Guard boats, while 3,000 police were on full alert ashore.
Several thousand demonstrators staged noisy rallies half a mile from the naval base, while others put to sea in a fleet of small boats to hurl insults from afar.
This week's visit was a very pale imitation of 1968.
This is not so much because of any change in underlying sentiment, but rather reflects a decline in radicalism in Japan.
The revolutionary ferment that thrived on university campuses here in the late 1960s and '70s is only a distant memory. For one thing, there is no really strong issue on which to focus dissent as there was then (the Vietnam war, educational reform, the construction of the new Tokyo international airport, etc.).
The radical fringe has been badly discredited by excesses such as the lynch murders within the ranks of the notorious Red Army of comrades not considered to have the right revolutionary spirit.
Founding members of the Red Army, now in foreign exile (North Korea, the Middle East) have confessed in print regrets for such activities which alienated public opinion and defeated hopes for an internal revolution against Japan's conservative rulers.
On university campuses today the emphasis is more on the prospects of getting a job during a business recession than on esoteric issues connected with ills of modern society or of political ideology.
Nevertheless, the Enterprise visit is controversial. It comes at a time when Japan's entire defense policy, especially the growing alignment with the Soviet confrontational approach of the Reagan administration, is being questioned.
As the carrier docked at Sasebo, a national newspaper was carrying a new public opinion poll showing 72 percent of those polled were uneasy about the defense-boosting desires of Prime Minister Yasuhiro Nakasone.
The Enterprise visit is also opposed because of a belief that it is carrying nuclear weapons in defiance of a government ban on the manufacture or presence of such weapons on Japanese territory.
This involves the Tokyo government in a typical political contortion, however. It upholds the ban in public, but at the same time acknowledges that Japan is relying on the American nuclear umbrella for security - protection that is meaningful if American ships, submarines, and aircraft operating around Japan are nuclear-armed.
Sasebo, it should be noted, is only a stone's throw from the atomic-bombed city of Nagasaki, where memories are still vivid of the horrors of nuclear war.
To many Japanese, it is not an American nuclear umbrella over their country but a nuclear magnet, inviting Soviet retaliation should war ever break out between the two superpowers.
American military bases and the US-Japan security treaty mean that Tokyo has firmly committed itself to one side in the confrontation and should be treated as an enemy by Moscow. Soviet propaganda aimed at Japan continually hammers away at this point.
Instead of violence, opponents of government policy are adopting a more peaceful, constitutional approach to tap the widespread uneasiness felt by the Japanese middle class.
A petition against the nuclear arms race, for example, has so far attracted 32 million signatures and is still growing, according to organizers who hope to achieve a final target of 70 million.
And a Japanese version of the Green Party, West Germany's antinuclear and environmentalist group, has just been formed in the city of Kobe. The group has 500 members who plan to support nine candidates in forthcoming municipal elections as a first stage to political influence.
Similar moves are under way in other parts of the country.