Kuwait's unexepctedly feisty National Assembly once again has served notice on a somewhat embarrassed government that it has no intention of becoming a rubber stamp.

This time it has passed a law prohibiting embassies from importing or manufacturing locally any kind of alcoholic beverage -- a prohibition even more severe than any in rigorously dry Saudi Arabia. The 29-to-O vote in mid-February, which took effect this month, has outraged the western diplomatic community here and brought charges of hypocrisy from many liberal-minded Kuwaitis.

Revived in February 1981 after a five-year suspension for bad behavior, Kuwait's 66-man National Assembly Sabah family presumably expected after radical Arab nationalist and pro-Iranian Shiite members were mostly gerrymandered out of their seats in the last elections.

In the two years of renewed parliamentary life, the assembly has veered left and right on its path to democracy, a path that has put the Sabahs, progressive by Persian Gulf standards, in a quandary.

Among its most controversial decisions opposed by the Sabah-led government have been votes barring Kuwaiti nationality to non-Moslems, rejecting women's right to vote, blocking an attempt to curb press freedom and refusing funds for the Syrian-manned Arab peace-keeping force in Lebanon.

In addition, the assembly has just signaled that the government's proposed amendments to the constitution expanding the ruling emir's powers have no change of getting the necessary two-thirds majority.

It is unclear to an outsider how such an institution -- the only one of its kind in the Persian Gulf's Arab states -- took root in the harsh desert of the Arabian Peninsula, where autocratic tribal and family rule prevails. The explanation seems to lie in the history and personality of this oil-based city-sate of 1.4 million people, which has the highest per capita income in the world.

Kuwaitis say their hybrid "Arabian democracy" stems from the highly mobile and cosmopolitan nature of their society, a tradition of consultation, and wealth-sharing between the leading merchant families and the Sabahs, who have ruled since 1756. Another factor is the size of the all-male, "first-class" voting population -- 43,000 in 1981.

Compared with western-style democracy, Kuwait's version still seems quite limited. There are no political parties, voting is limited to 3 percent of the population, and the prime minister is always the crown prince, chosen by the Sabah family and virtually immune to a vote of no-confidence.

But in the context of the Arab state of the gulf, where "democracy" goes no further than weak consultative councils of appointed elders, Kuwait's National Assembly seems light years ahead in the emergence of any real democratic institutions.

Remarked one western diplomat, "There are not many assemblies in the Third World where deputies are free to stand up and criticize the government" as they do here.

The present 50 elected deputies were expected to make up a far more accomodating body than the previous assembly, which publicly insulted the ruling family and questioned its right to rule. Emir Jaber Sabah suspended it in 1976 on the expressed grounds that the shock waves from the Lebanese civil war were threatening Kuwait's stability.

The Feburuary 1981 elections saw the purge of all leftist Arab nationalists and all but three pro-Iranian Shiite Moslems from the assembly. But their place was taken by a half dozen Islamic fundamentalists who are proving more astute in pushing through bills reflecting their views.

One examples was the ban on alcohol for the embassies, a measure that the government opposed but could not vote against without being viewed as anti-Islamic. Instead, more than half the assembly, including all 16 ministers, stayed away for the vote.

More weighty is the constitutional issue now before the assembly: a set of 17 amendments to the 1962 constitution whose affect would be to broaden the emir's power at the expense of the legislators'.

Last December, the assembly voted 37 to 27 in favor of the principle of amending the constitution, with the government mobilizing its "Bedouin lobby" and 15 ministers serving as appointed deputies to push the vote through. But most of the assembly's leadership, including seven of the eight committee chairmen, voted no.

In early March, the Legislative and Legal Affairs Committee submitted its report, recommending 6 to 1 that all the amendments be rejected.

The emir has avoided a head-on confrontation at least temporarily by withdrawing the proposals. But the committee wants to bring the issue to a vote anyway, according to its chairman, Issa Shahin, who has a degree in political science from Indiana University.

In an interview, Shahin said it had become "rather clear that the majority of the assembly and outside the assembly is against any amendment affecting the democratic process in Kuwait."

One amendment he cited as among the most objectionable to the committee concerns a constitutional provision setting forth the principle of the separation of powers among the executive, legislative and judicial branches. The amendment would give the emir the right, in "exceptional circumstances," to issue decrees having the power of law.

Shahin said the problem is that the government does not indicate what constitutes "exceptional circumstances." He called it "an open door" for the ruling family to issue decrees "any time they wish."

In mid-May the government withdrew the amendments because it sensed the atmosphere "for objectivity and calm" in debate was "no longer available."