Many years ago, a movie theater called the Brattle near Harvard University would show the film Casablanca over and over. The students who watched would chant the lines along with Humphrey Bogart and Ingrid Bergman. The viewers knew every element of the story line from memory — and it never changed.

That’s the way the Mideast peace process used to seem to a correspondent who followed it for decades. The actors shifted every so often — although there were many who refused to leave the stage short of the cemetery — but the script hardly varied.

Yet, as I head off for an extended trip to Israel and the West Bank, preceded by a visit to Turkey, a lot of old story lines seem to be ending, with little clarity about new ones. The key players in Jerusalem and Ramallah — and Ankara — have rewritten their roles, but no one’s certain where the characters are headed. Meantime, the paramount Mideast actor, Uncle Sam, seems to be retreating from star status, which makes the plotline even more unclear.

One of the most startling role shifts has been undertaken by Turkey’s leaders. Ankara was viewed as a reliable, Western-oriented NATO partner during the decades of Cold War, a Muslim country with an allied military and a secular bent.

Many viewers now believe they can recite the new script for Turkey: Prime Minister Recep Tayyip Erdogan and his ruling Justice and Development Party have reoriented the country toward the East, embracing Iran and Hamas, and rupturing their old relationship with Israel. Erdogan, so goes this plotline, had long been waiting for an excuse to liberate his inner Islamist tendencies, and now hopes to become the leader of the region’s Muslims. In this script, he is no longer an ally to be trusted.

But is the story so straightforward? Could common U.S.-Turkish interests in Iraq and elsewhere help U.S. officials maintain a stable, if often prickly, relationship with Ankara? Did Israel exacerbate a breach with Ankara that could have been mended? Most important, is Turkey’s leading actor, Erdogan, a pragmatic Muslim politician or an Islamist ideologue with a mission? This drama is still in its early stages, with the final script unwritten, which is why it will be so fascinating to visit now.

The narrative line in Jerusalem is even more blurry. The peace process between Israel and the Palestinians, ongoing for nearly four decades, is either finally dead or about to reach a climax. What’s most amazing is how many Israelis are uncertain about which of those options their prime minister wants.

Just as Turks argue over the real nature of Erdogan, Israelis argue over what “Bibi” Netanyahu is really thinking or seeking. (Nor is it clear what Palestinian leader Mahmoud Abbas wants out of the current negotiations or whether he will be eclipsed by his younger guard.)

Haaretz columnist Israel Harel says Benjamin Netanyahu has done “an ideological about-face” and is “abandoning beliefs he imbibed with his mother’s milk.” Harel believes the Israeli leader is ready to give back most of the West Bank for the establishment of a Palestinian state.

Yet in the same Israeli paper, writer Aluf Benn argues that Netanyahu is secretly encouraging his hard-line foreign minister, Avigdor Lieberman, to take rigid positions in public that rule out any peace deal. According to this plotline, the Israeli leader can appease President Obama while ensuring that talks go nowhere.

Meantime, Israelis on all sides, and Palestinians, too, sense that prospects for a “two-state solution” — the peace-process story line for decades — are just about over. Yet no one has come up with an alternative script that has any prospects of success.

One reason it is so hard to devise a new narrative is that the juiciest role in the peace process is going begging. Ever since Israel’s founding, the United States played godfather and prodded Israelis and Arabs to the table. Jimmy Carter arm-twisted Egypt and Israel into a peace deal; Bill Clinton tried mightily, and failed, to do the same with Israel and the Palestinians.

But George W. Bush let the peace process go hang in favor of his Iraq venture, and it’s hard to figure out what Obama’s Mideast team is doing. Years of Iraq folly and failures in South Asia have undermined our influence and credibility in the region. And as U.S. influence wanes, others — like Iran and Turkey — seek to fill the vacuum, but they can’t take over the role America once played.

So when I visit the region this time, I will be a seeker — trying to discern the outlines of a new drama. That means trying to figure out what Erdogan, Netanyahu and Abbas want, whether new actors are emerging, and where the new narratives are headed even as they are being written. There was something comforting in knowing the old script and all the players. But those days are gone.

— Trudy Rubin is a columnist and editorial board member for the Philadelphia Inquirer. trubin@phillynews.com