The Reagan administration is taking the expected hard-nosed approach to the November summit with Mikhail Gorbachev. But what is unexpected -- and disturbing -- is the note of plaintiveness and defensiveness, verging on a lack of self-confidence, emerging from official statements and attitudes. It is all the more strange and out of character in an administration that claims to have restored American power and to be riding a historic wave of national renewal.

A telling sign came in the clenched- teeth White House complaint that President Reagan is not being given an opening to the Soviet public comparable to the opening Gorbachev has been given this week by Time magazine and a delegation of American senators. As though there were any such thing as a Soviet public opinion that its Kremlin masters would allow to be influenced by a silver- tongued American politician.

Another sign is the decision to schedule an early test of an anti-satellite (ASAT) weapon, though the original instrumented target that would give full military value from the test isn't ready. The reported purpose of the test, in the view of officials who pushed for it, is to show resolve to the Soviet Union. As though one more test of one more weapon were required to communicate American will.

In his interview with Time, the Soviet leader, who, according to administration legend presides over a failing system, did not find it necessary to make a point of Soviet will. He appeared to assume that not many people would doubt the Kremlin's readiness to make the country do whatever its leaders decide is necessary. The quality Gorbachev chose to project was reasonableness: hence the various arms moratoriums he has proclaimed and appealed to Reagan to match. Aside from its tactical value in cultivating American and world opinion, the Gorbachev emphasis is mature and becoming for a great power.

Would you not think that, on the eve of a summit, the United States would be advertising its success in restoring American power, rather than its anxieties about slippage? That it would be confidently putting into practice the theory it has long formally espoused that its trillion-dollar buildup puts the United States in a position to get good-for-America agreements with Moscow? That it would have the assurance to act on its calculated judgment that the Soviet Union needs a respite from arms building to tend to other needs?

One Carter year and nearly five Reagan years into the biggest peacetime military buildup ever, this administration still worries that the United States is somehow behind and that the Soviet Union and others will take us for weaklings.

Most administration critics are ready to accept without cavil its early contention that the Soviet Union took advantage of American distractions in the 1970s and sought one-sided military and strategic advantage. But not even its supporters seem ready in any number to accept the plain suggestion coming out of the Pentagon and elsewhere that the basic Soviet-American equation has not really changed since the 1970s and that therefore the American people must buckle down and support both a greater buildup and a tougher negotiating posture.

Nor is there much detectable enthusiasm, again even among his natural supporters, for the particular way in which the president is pursuing his Strategic Defense Initiative. Two- plus years of intensive discussion in the political and scientific communities have failed to win Reagan a strong following for his commitment to press on toward deployment of Star Wars. The informed consensus is perhaps summed up by former defense secretary James Schlesinger, no softy: "I see no hope of progress toward a serious, substantive agreement unless the president makes SDI negotiable."

There are suspicions that some in the administration, fearful lest their

chief tempt the

wages of overcommitment, are

1) carefully setting standards for

SDI that they

count on its being unable to meet (in

cost effectiveness

and invulnerability), or 2)hoping

to use it somehow as a bargaining chip in negotiations, possibly at the summit. But the president has yet to give any visible comfort to these tendencies.

In short, Reagan has given Gorbachev a huge opening. The Russian played directly and shrewdly to it this week by offering the possibility of a grand package: deep cuts in offensive arms and restrictions on SDI. A confident administration would not be complaining of Soviet "propaganda." It would be claiming that the Soviet moves induced by wise and firm Reagan policies constitute a major potential breakthrough in the American interest.