You can say goodbye to the Israel and to the Middle East you used to know. Much else may still be unclear in the region -- but not that it has been forever changed by the latest war.

Remember the Israel whose wars used to be fought to ensure her survival? It's gone for now, the stuff of fading newspaper clippings and history books. Perhaps nothing distinguishes Israel's invasion of Lebanon more than that it was initiated for political purposes, not for survival.

Or remember the West Bank autonomy talks and the sticking point of PLO? Some may be urging Israel to get those negotiations back on track as soon as possible now, but with the PLO decimated, what finally ought to be clear is that the those talks are dead -- and have been for some time -- as a potential solution to the Palestinian question.

Or recall the Arab "oil weapon" that emerged during the 1973 war with the OPEC embargo -- the long lines and surging prices at American gas stations, the increased U.S. political pressures to make the Arabs happier? The Arab oil producers obviously would have a far more difficult time playing an oil card today, even if they wanted to. But the issue has not even been raised -- and one has to wonder whether it will indeed be raised again in relation to U.S.-Israeli relations. To what end would it be used?

Many other Mideast questions are also open now: Who will speak for the Palestinians? What will the Soviet role be in the region? How will U.S.-Israeli relations be affected? While we'll have to wait for the dust to clear to start getting some answers, other critical changes already are evident.

Start with the issue of Israeli survival, which has overridden all other Israeli concerns since creation of the state. If Israel achieves its goal of banishing the PLO and the Syrian army from Lebanon, Jerusalem probably will begin paying an ironic price: After her impressive victories, Israel will find it more difficult to make a convincing case abroad that her survival is any longer at issue (even though, in the long run, it may well be).

The invasion of Lebanon, of course, marks the first war Israel has fought without Egypt opposing her. This removal of Egypt has made it possible for Israel to contemplate limited military actions without considering how the largest Arab country will respond.

In this war, Israel neutralized the Syrians' Soviet-built, surface-to-air missile system, the same system that crippled the Israeli air force in the 1973 war and contributed to the heavy casualties Israel suffered then. Israeli armor, especially the Israeli-designed and Israeli- built Merkava tank, met and bested the Soviet T-72, previously considered in some circles the best tank in the world.

The removal of Egypt and Israel's success in neutralizing Syrian missile defenses means that Israel can, if she chooses, again deploy her air force as an instrument of policy against her neighbors.

Much of this is heady stuff for Israel, even though her public is increasingly depressed by the growing Israeli army casualties -- more than 300 dead and 1,500 wounded, according to official Israeli sources -- not to mention the Arab civilian casualties for which some Israelis feel equally pained.

The war in Lebanon, begun purportedly to protect the northern borders from terrorist attack, was expanded to include restoration of a stable equilibrium in Lebanon, free of foreign presence -- Palestinian, Syrian or Israeli. This avowedly political goal has raised, alsoofor the first time, the specter of dissent and demonstrations about the war while it is still going on. For the first time in Israel's history, Israelis -- a minority of them, to be sure, but a pres, probably no amount of added effort coestigious and influential minority -- are calling for an end to the war.

If the Israeli government does not achieve its maximum goals, Menachem Begin may well fall from power. As a proportion of population, the 300-plus Israelis who have died are roughly equivalent to 20,000 American casualties. Approximately 55,000 Americans died in Vietnam. Casualties of this magnitude are an enormous trauma for Israelis, and it is hard to believe they will forgive a government that involved them in a controversial war without accomplishing everything the government said it was seeking.

In fact, cracks have already begun appearing in the Knesset. The opposition Labor Alignment Party, which supported the government when Israeli troops first invaded Lebanon, has begun attacking the government for expanding the war. Labor's only hope of returning to power any time soon is if the Begin government fumbles in a way that brings real pain to Israelis. The war in Lebanon, if it drags on indefinitely, has that potential.

In the name of survival, Israeli defense policy seems to be broadening its reach far beyond its borders. Defense Minister Ariel Sharon, a fierce and relentless advocate of maximalist positions, last December outlined a little-noticed but sweeping position on Israel's strategic concerns. The most immediate circle of concern, he said, was the traditional confrontation states adjoining Israel. The second circle included Arab countries whose growing military power enabled them to send forces to aid the confrontation states or to contemplate long-range attack by sea or air.

Finally, Sharon said, were countries whose "political strategic status and orientation can dangerously influence Israel's national security. In other words, beyond the Arab countries in the Middle East, the Mediterranean and the Red Sea, Israel's sphere of strategic and security interest must be broadened to include in the 1980s countries such as Turkey, Iran and Pakistan and regions such as the Persian Gulf and Africa, particularly the countries of north and central Africa."

That is quite a tall order for a nation the size of New Jersey with a population equal to Maryland's. Assuming Israel gets what it wants in Lebanon, will she feel free to intervene elsewhere around her as events take a turn her government considers threatening?

It is also clear that the autonomy talks -- the remaining major item on the peace-process agenda with Egypt -- have been cast into an entirely new light.

The Israeli government has been trying to replace the PLO's political structure on the West Bank with its own non-radical alternative. Israel is now free to take advantage of the PLO's political disarray to impose a political solution on the West Bank and call it autonomy. The PLO is probably not in a position to organize much resistance there.

Having chosen to project her power beyond her borders, Israel may now find that power increasingly burdensome and even problematic as she negotiates with the United States over how much military and economic aid she will receive. Israel is fighting now to impose a political solution on Lebanon. What will she do if the various Lebanese factions are unable to come to terms with each other?

From a strategic point of view, what makes Israel's position unique and particularly difficult for such a small country is that she is surrounded by other relatively small but mostly wealthier countries that, with the single and recent exception of Egypt, have never been willing to recognize her existence. Other small countries arm for war. Israel has had to arm herself for Armageddon. Thus armed, she has fought wars, able to win because her army is well-trained, because her equipment has been superior and better-maintained than her enemies' and because -- in 1967 and 1973 -- she had no choice.

Seeing the Israelis brush aside any military force in its way with apparent ease, it may be tempting now for America to respond to Arab pressures for a policy that tilts toward the Arabs. Indeed, with [WORDS ILLEGIBLE] , whose Bechtel Corp. did billions in business with the Saudis, taking over at the State Department from Alexander Haig, Israeli fears are heightened that such a tilt may occur.

What form could such a tilt take is not hard to imagine, but to what end is less clear. What, besides autonomy, is left on the table at the moment? It is hard to imagine that Saudi Arabia, much less Jordan, wants a Palestinian state established on the West Bank. Pressed to conclude the autonomy negotiations, now that the PLO has been humbled, the Israelis may bring forward their own Palestinians, install them in authority and grant them powers that the Israelis will call "full autonomy."

The United States may press the Jordanians to join in the peace process now that the PLO has been humbled and the opportunity presents itself for Jordan to reassert its interest in the West Bank. Even though no Arab state did anything more than pay lip service to the PLO, it would not be surprising to find the Jordanians -- and the Saudis -- reluctant to come anywhere near negotiations with the Israelis so soon after the PLO has been humiliated.

Until we know more about what passed between the United States -- or more precisely, between Haig -- and the Israeli government prior to the Israeli invasion of Lebanon, it will be hard to know whether American influence in Israel has reached a low-point.

The United States could, as a short-run form of pressure on the Israeli government, reduce economic aid, military aid or once again stop the flow of weapons to Israel. The Israelis have seen these moves before and have developed a cynical attitude about them. Given time, these pressures have always passed, and the Israelis have gotten what they wanted.

This time, if the Reagan administration decided to tilt toward the Arabs, it could be different. The administration could -- for what still remains unclear -- reduce arms shipments or suspend them indefinitely until Israel showed signs of doing whatever it was that the administration wanted done.

Alternatively, the administration could follow the line apparently advocated by Defense Secretary Caspar Weinberger and provide Jordan with a new air defense system.

Scaling back Israeli arms or allowing the qualitative (not quantitative) edge that the Israelis now enjoy to dwindle are only two possibilities that make apparent rather than real sense.

The trick for American foreign policy, unless it wants to abandon Israel altogether, is to find a way to keep her strong enough to insure her survival but still dependent enough on the United States so that Israeli clashes with U.S. interests are kept to a minimum.

The picture emerging still remains murky. Is the war in Lebanon the end of a cycyle of violence, or the beginning of a new one? Will the PLO be supllanted by a new more moderate Palestinian nationalist movement, or will the PLO emerge more violent and radical than before? Will Israel, having defeated the PLO on the battlefield, now be willing to seize the initiative and press for a solution to the Palestinian problem that will involve compromise on both sides, or will she impose a solution that satisfies no one but herself?