I got an email last weekend from a gentleman asking my advice on how to counter Israel’s “delegitimization” in the United States. This column constitutes my response.

To counter Israel’s “delegitimization,” you must first understand what “legitimizes” Israel in the first place. For three different groups of Americans, there are three different answers.

Group number one consists of non-Orthodox American Jews, especially those middle-aged and older. For them, what legitimizes Israel is its status as a place of Jewish refuge. In the early twentieth century, many American Jews rejected Zionism. But American Jewish anti-Zionism died in the 1940s because the Nazis proved that Europe’s Jews were not safe and the rest of the world proved that it would not provide them sanctuary. Thus, most American Jews concluded, the world needed a country dedicated to Jewish refuge. Three quarters of a century later, that argument remains largely uncontested among older American Jews. They may question Israel’s policies and dislike its leaders. But since they believe the world still needs one country that will take in Jews who have no place else to go, they don’t question Israel’s legitimacy as a Jewish state.

Group number two consists of conservative American Christians and many American Orthodox Jews. For them, what legitimizes Israel is the Bible. The land between River and the Sea belongs to the Jews. It says so in Genesis. And no politician, be he the President of the United States or the Prime Minister of Israel, has the right to undo the covenant forged between the Jewish people and God.

Among groups one and two, Israel’s “delegitimization” is not a problem. Group number two could theoretically question Israel’s legitimacy if an Israeli government relinquished Biblically-mandated land. In 2006, for instance, evangelical leader Pat Robertson suggested that Ariel Sharon’s stroke was a punishment from God for his decision to evacuate settlers from Gaza. But given that no further Israeli territorial withdrawals appear likely, this kind of right-wing, religiously-ordained “delegitimization” is unlikely to cause Israel problems anytime soon.

The real challenge, therefore, is among group number three: the secular whites, African Americans and Latinos who dominate the American left. For them, what legitimizes Israel is neither the Holocaust nor the Bible. It’s democracy. Since Israel’s creation, Palestinian activists have argued that a state constructed to safeguard and represent one ethno-religious group (Jews) is inherently racist. But what has kept that argument from gaining traction, even among American progressives, is Israel’s reputation as a democracy. That’s why groups like AIPAC constantly cite the “common values” of “democracy, the rule of law, freedom of religion and speech and human rights” that are “shared between the United States and Israel.” Because AIPAC knows that it is democracy and human rights that validates Israel among those Americans for whom Israel’s Jewishness alone is not legitimacy enough.

Israel’s problem is that its almost half-century-long control over millions of West Bank Palestinians who lack citizenship and the right to vote in the country that controls their lives, and live under a different legal system than their Jewish neighbors, makes it harder to legitimize Israel as a democracy.

Israel’s undemocratic control of the West Bank isn’t new, of course. But since the 1990s, several changes have made American progressives less tolerant of it. First, Israel no longer has a prime minister who seems remotely interested in ending the occupation by creating a Palestinian state. Second, Palestinians have now lived in the United States long enough to birth a generation of American-born activists who fluently speak the language of American left. When these Palestinians activists, who are themselves Americans of color, speak to other Americans of color about what they describe as a racist, colonialist regime that denies basic rights to the indigenous, non-white population, African American, Latino and Asian heads nod.

Third, a growing number of younger, secular American Jews do not themselves grasp the necessity of a Jewish state of refuge. Their grandparents may remember the Holocaust. Their parents may remember the exoduses to Israel from Ethiopia and the former USSR. But these American Jewish millennials have never seen any large-scale migration to Israel by Jews fleeing state-sponsored anti-Semitic persecution. And since they have experienced barely any anti-Semitism in their own lives, they can’t imagine needed Israel as a refuge themselves.

Contemporary European anti-Semitism may convince some of the necessity of Zionism as refuge. But for others, growing up in a world in which the vast majority of Diaspora Jews live in liberal democracies in which they enjoy equal citizenship makes the refuge argument seem anachronistic.

This does not, in itself, make them anti-Zionists. But it means that when they grow alienated from Israel’s actions, they are more willing than their parents and grandparents to question why a Jewish state needs to exist at all, especially when they hear other young progressives — with whom they generally agree — raise the question. And especially because they vehemently oppose the intermixing of religion and government in the United States. A 2007 study by the sociologist Steven M. Cohen found that while 81 percent of American Jews 65 and older declared themselves “comfortable with the idea of a Jewish State,” the figure dropped to 54 percent among American Jews under 35.

Skeptics may wonder why only Israel is suffering this process of “delegitimization.” There are, after all, plenty of countries that violate democratic norms more profoundly than Israel does. Why aren’t American progressives trying to boycott and overthrow their political systems? Partly, it’s because activists from other countries haven’t asked them to. If a broad network of Saudi civil society groups had launched a decade-long campaign aimed at boycotting, divesting from and sanctioning the regime in Riyadh — as Palestinian civil society groups began doing to Israel in 2005 — they’d have garnered some support among American progressives too.

Partly, it’s because Palestinian activists frame Israel’s behavior as the domination by a white, western population of an indigenous, non-western one. To my mind, that’s simplistic and misleading. (I’ve written in detail about why I think Israel is not an apartheid state.) But with this frame, Palestinians tap into the left’s singular focus on colonialism and racism. Why are left-wing Americans more upset about Israeli human rights abuses than Egyptian ones? For the same reason left-wing Americans were more upset about white rule in South Africa than Idi Amin’s rule in Uganda. And for the same reason left-wing Americans poured out into the streets to protest America’s invasion of Iraq, and the World Bank’s development policies, but not the regime in North Korea. Because leftists get more upset when “Western” regimes commit human rights abuses than when non-Western ones do.

Decrying this double standard may make Jewish groups feel like righteous victims, but it will have no effect. Neither will pointing to Israel’s technological breakthroughs or its good works in Haiti. Israel’s treatment of the stateless Palestinians over which it rules is not a public relations problem. It is a moral problem.

The only way to stop Israel’s growing “delegitimization” among American progressives is to convince those progressives that Israel can be both a democracy and a Jewish state. And the only way to do that is to prove that Israel is making a serious effort at ending the occupation and thus becoming, once again, a country that offers citizenship and the right to vote to everyone under its domain. That won’t end the BDS movement. Die-hard anti-Zionists will still call a Jewish state racist within any borders. But concrete moves to end the occupation will blunt the BDS movement’s growth. They will make it far less likely that the people who now cheer Bernie Sanders will embrace anti-Zionism in the years to come.

The struggle for Israel’s legitimacy and the struggle for Israel’s democracy are one and the same. Any organization that fights for the former without fighting for the latter is wasting its time.