Whether or not Benjamin Netanyahu's right-wing coalition prevails in Tuesday's election in Israel, Americans face a wrenching decision about how to respond to the country's drift away from liberal democracy and toward the permanent imposition of apartheid on the Palestinians of the West Bank.

Thirteen years ago, when Jimmy Carter used the language of systematic institutionalized oppression to describe the emerging relationship between Israel and the Palestinians, he inspired harsh criticism. So did Barack Obama, when he tried during the opening years of his presidency to force Netanyahu's government to halt the settlement expansion that seemed like the opening moves in a slow-motion annexation of contested land in the West Bank. We've seen defensive indignation again in recent months, in response to Rep. Ilhan Omar's sloppy formulations about the character of America's bilateral relations with Israel.

Yet the possibility from which Carter, Obama, and Omar have recoiled is now unfolding before the eyes of the world. No longer a prophecy about the future, it has become a description of an aim actively embraced and pursued by the Israeli prime minister. It is now undeniable that a policy of annexing the West Bank and turning its Palestinian residents into permanent second-class citizens of Israel, lacking political rights, has gone mainstream. Indeed, Netanyahu made a promise to pursue such a policy his closing argument on the weekend prior to the vote. This is a remarkable turn of events that cannot help but alter the way Americans think about our relations with and unconditional support for Israel.

Netanyahu's embrace of annexation comes as the final step in a series of moves over the past year. Last July, his governing coalition pushed through a law declaring Israel "the nation-state of the Jewish people," relegating the country's substantial non-Jewish population to uncertain status. Then, in February, Netanyahu engineered a deal between the far-right Jewish Power party and another ultranationalist party (Jewish Home) that gives these right-wing radicals a greater chance of winning seats in the Israeli Knesset and joining Netanyahu's governing coalition. (The Israeli Supreme Court later banned the head of the Jewish Power party, Michael Ben-Ari, from seeking office, but other members of the party remain eligible to run.) Most recently, Netanyahu helped persuade President Trump to recognize Israeli sovereignty over the Golan Heights, territory seized from Syria during the Yom Kippur War of 1973.

That last move leads directly to Netanyahu's statement of this past weekend about annexation of the West Bank.

Despite what many Americans think, Israel is not, strictly speaking, our ally. (Alliances are defined by mutuality among nations, and no one would expect Israel to come to our defense if we were attacked by a third party.) Israel is our client, and we are its patron to the tune of more than $3 billion a year in aid. In return for that support, Israel gives us access to intelligence gleaned from its many agents and assets in the Greater Middle East. That support also gives us considerable leverage over Israeli actions, but only if we use it. More than any previous president, Trump has opted not to use it — to give Netanyahu a green light to do pretty much anything he wants. And Netanyahu is taking full advantage of the opportunity. Fully aware that his American counterpart may well have less than two years left in office, the Israeli prime minister appears to understand the need to move quickly.

Netanyahu has every reason to suspect Trump will support a move to officially incorporate all or substantial portions of the West Bank into Israel proper. The question is how American voters will respond.

Americans like to think of themselves as champions of freedom and democracy around the globe. The truth is far more muddled. (We hate dictatorship in Iraq, Libya, Iran, and Venezuela, but we can live with it in China and Syria, and we positively embrace it in Saudi Arabia.) We also like to imagine that our actions around the world are motived by a hard-nosed assessment of our national interests. The effort to bring together those competing visions of the country leads centrist politicians like George W. Bush, John McCain, and Hillary Clinton to suggest that the pursuit of our interests coincides perfectly with the promotion of freedom and democracy everywhere. That is a consoling and simplifying fiction.

Israel has long been a particularly hard case for such acts of consolation and simplification. On the one hand, it's a small state founded by refugees from the Holocaust; it's in a dangerous neighborhood surrounded by much larger, hostile powers; it has until now been the only democracy in the region; and its biblically rooted national story resonates in complicated ways with America's own quasi-theological vision of itself. On the other hand, Israel has triumphed decisively in its wars with its neighbors since the late 1960s, it has held onto the land acquired in those conflicts, and it has spent the past five decades building settlements on that territory while failing to extend political rights to non-Jews who live there.

As long as the parties involved kept hope alive for the founding of a Palestinian state on the West Bank, Americans could tell themselves that the settlements were temporary — that most of them would be dismantled and removed as soon as a final peace deal was reached. This was always unlikely, and it's become less so with each passing year, as the number and size of the settlements has increased (well over half a million Israelis now live in the West Bank), as parties that support expanding them have gained in strength, and as those parties have become integral to Netanyahu's Likud Party holding onto power. Now that Netanyahu has endorsed outright annexation, all hope for an outcome that avoids the imposition of an Israeli version of apartheid has been dashed.

Let's leave Israel's assessment of its national interests to the Israeli electorate. The question that matters for the United States is what it would mean to continue identifying and aligning itself with a state that actively chooses to institute and codify a form of rule that so closely resembles the brutal racial caste system that prevailed in South Africa until 1994. Trump has no problem doing so because he couldn't care less about the promotion of freedom and democracy. But are a plurality of Americans ready to follow him down the path toward explicit endorsement of authoritarian repression? And if so, why? What American interests would be advanced by doing so? Is Israeli intelligence really so irreplaceable? Regardless of how we ultimately answer these questions, there will be no avoiding raising them. A painful, awkward, and nasty national debate awaits us.

For no one will that debate be more painful, awkward, or nasty than American Jews. Author Peter Beinart has seen it coming for years — the growing tension between Jewish liberalism and Zionism. For the first several decades of Israel's existence, the two were widely treated as synonymous. But they have been moving apart for years. Younger American Jews are already much less inclined than their parents and grandparents to grant Israel the benefit of the moral doubt in its treatment of the Palestinians. If Israel annexes the West Bank, that gap will become a chasm. The 30 percent of American Jews who support the Republican Party may go along, but many of the rest will not. And that will mark a massive change in the Jewish community of the United States.

Whatever the results of Tuesday's elections, American's special relationship with Israel is headed for the rocks.