The Israeli government's recent turn toward a tougher policy in the occupied West Bank and Gaza strip, although bewildering and insensate to many on the outside, actually is a textbook example of coalition pressure politics at work in this volatile, issue-oriented society.

The hard-line stand that Prime Minister Menachem Begin's government has taken in the past weeks -- the arrest and planned deportation of Nablus Mayor Bassam Shaka, the announcement of its intention to triple the Jewish population in the West Bank with 31 new settlements, and the increasingly strident talk about asserting Israeli sovereignty in the occupied territories -- seemed to baffle a world audience conditioned by the Camp David peace accords to expect conciliation and moderation.

The world seemed to be asking, in collective astonishment: How can Israel expect to negotiate with people they seem so bent on humiliating?

The answer, in its simplest form, is that most of Israel's recent combative decisions affecting Palestinian interests can be traced back to one momentous event -- the ruling a month ago by Israel's High Court of Justice that the Elon Moreh settlement near Nablus must be dismantled.

As in most momentous political events, especially those that go against the gain of deeply rooted ideologies, there were winners and losers in the battle over Elon Moreh. But the losers in this case -- the ultra-nationalist Gush Emunim settlement movement and its allies in the National Religious Party -- have not resigned themselves to defeat.

Instead, they are using Israel's parliamentary system of government, with its tradition of intricate coalitions formed out of subcoalitions, to their best advantage, forcing Begin's shaky government into positions that seem to flout the placative spirit of Camp David and attempting to trade off their rocky hillside outpost for a firm commitment by the government to an aggressive policy of building Jewish civilian settlements throughout the occupied territories.

Since the founding of the Jewish state 31 years ago Israel politics have been like a Chinese box, with coalitions of parties forming both the incumbent governments and the opposition alignments, and with coalitions of splinter groups within the larger blocs.

While this system succeeds well at giving voice to the various shades of political opinion in Israel -- and there are many -- it allows relatively small minorities to exert disproportionate influence on government decisions.

For example, the National Religious Party has 12 seats in the 120-member Knesset, but it is the pivotal partner in Begin's Likud coalition, which holds 65 Knesset seats. Should the National Religious Party leave the coalition, or fail to support it on a vote of confidence, Begin's government would collapse. If the other religious party, Agudat Yisrael, with four Knesset members, were to quit the coalition -- as it has threatened to do in its fight to toughen the abortion law -- the government could be one vote away from defeat.

The price Begin has had to pay for the continued support of the National Religious Party has been to give it the dominant voice in Israel's settlement policy in addition to its traditional control of religious matters, because in the eyes of many fervently nationalistic Jews, religion and settlements are inseparable.

In order to win the National Religous Party support for -- and therefore Knesset approval of -- the original Camp David accords last year, Begin was forced to agree to pursue an aggressive policy in negotiating the future of the West Bank and to speed up settlement activity in the face of intense pressure by the United States and Egypt.

It was not by chance that Education Minister Zevulun Hammer, a National Religious Party member, was manager of a proposal that will increase the Jewish population in the occupied areas by 10,000 to 15,000 persons a year, at a staggering estimated cost of $5 billion. The Cabinet gave final approval to the settlement program last week.

Moreover, Begin is under similar pressure -- if, indeed, he needs prodding -- from his party's own right wing, most notably from Agricultural Minister Ariel Sharon, the most vociferous advocate of settlements in the government.

To Shaaron, and his Gush Emunim constituency, Elon Moreh is a symbol of the Jews' Biblical right to settle anywhere in "Eretz Israel" (translated literally as "the land of Israel," but connoting what was Palestine west of the Jordan River).

Elon Moreh is the place where Abraham first settled, according to religious tradition. The threats of the settlers there to resist forcibly their evacuation are based primarily on this mystical attachment to the land.

It is small wonder, then, that Begin's government, desparately anxious to honor the High Court decree and yet wanting to defuse the growing crisis about Elon Moreh, compensated the sponsors of Gush Emunim activism with an ambitious settlement program, even if it happened to coincide with the arrival in Tel Aviv of an Egyptian negotiating team for talks on the future of the West Bank and Gaza Strip.

Almost simultaneously, the bizarre case of Nablus Bassam Shaka unfolded and drew the government overnight into unwittingly making a relatively ordinary Arab mayor a folk hero and martyr.

A sensationalized press account of Shaka's alleged expression of support for terrorists during a private meeting with a military official swept the Knesset floor just as Defense Minister Ezer Weizman, who had not read the account, entered the chamber. Weizman, facing a torrent of criticism from rightest members, impulsively announced that the government would "take action" against Shaka, which it did by arresting him and ordering him deported.

It was only after a revised and more moderate version of Shaka's statements had emerged, and after the mayors of all of the 25 towns of the West Bank and Gaza strip had resigned in protest, that the government declared that a pattern of pro-palestine Liberation Organization activities -- and not the reported statements -- would be the basis for Shaka's expulsion.

The government's decision on Shaka, like that in the settlement controversy, is less surprising when viewed in the climate of angry reaction to what the extreme right in Israel regards as a continuous policy of appeasing United States wishes concerning the West Bank, and in light of the threat of defections from the Likud to the newly formed Tehiya (renaissance) Party.Such defections, further splintering the fragile coalition, could erode the government enough to eventually cause its collapse.