In a moment of exasperation, Abraham Lincoln once challenged a political opponent: "If you call a tail a leg, then how many legs does a donkey have?" The surprised politician responded, "Five." "No," Lincoln answered. "The answer is four, because calling a tail a leg doesn't make it so."

Unfortunately, Lincoln's observation applies with particular force to contemporary Israel. The land from the Mediterranean to the Jordan River today has a population of six million Jews and 5.8 million Arabs. That is the sad reality, and calling Israel a Jewish state is becoming less and less accurate. In a few years, Israel will not be a Jewish state at all, but rather its population will consist of an approximately equal number of Jews and Arabs. Leading demographers now say that the Arab population is growing more rapidly than the Jewish population.

The time has come, therefore, for Israelis to decide what the country's future will be, where it is going and where they want it to go. To no one's surprise, the vast majority of Israeli Jews want to live in a Jewish state. Most Jews worldwide want the same thing – that Israel remain a Jewish state. The problem is that in its current borders, Israel is not a Jewish state.

The Center for Middle East Peace conducted a poll in Israel in which it asked the Jewish population, “Do you want to live in a Jewish state or a bi-national state?” 98% of the respondents replied that they want to live in a Jewish state. But it’s in the hands of the prime minister of Israel whether that 98% will be heard or not.

On paper and in speeches, Prime Minister Benjamin Netanyahu repeatedly reiterates that he is open to making peace with the Palestinians and to a two-state solution. But a two-state solution depends on two parties, on the Palestinians agreeing both to Palestine being a demilitarized state and to Israel retaining the approximately 5% of the West Bank on which 80% of the Israeli settlers live. The Palestinian leadership has agreed to the concept of equal land swaps that will accomplish this. But such a solution also depends on Israel agreeing to relinquish all the rest of the West Bank (along with proper security guarantees), and yes, painful as it is, to allowing the Palestinians to establish a state with East Jerusalem as its capital.

If Israel agrees to this, then it can extricate itself from the West Bank, and free itself of the 2.4 million Palestinians living there, 2.4 million people who do not want to live under Israeli rule but in a state of their own. And of course if proper security arrangements can be made, Israel can one day extricate itself from the 2 million Palestinians in Gaza whose maritime borders and whose airspace it still controls.

This is the choice confronting Israel, and the choice will ultimately lie in the hands of the prime minister, whether it is the current one or whoever follows him.

The boycotts, delegitimization and harm to Israel's international standing, of which the recent British parliament vote is the most recent manifestation, is increasing specifically because Israel is ruling over another people who seek independence.

The implications therefore of not helping to bring about a Palestinian state are as catastrophic for Israel as it is for the Palestinians. The Palestinians living under Jewish rule will grow in numbers and come to exceed and eventually far exceed the Jews. There will be a one-state solution, and the one-state that will either be a Jewish-controlled state without democratic rights for its Arab residents, or a state in which the Jews are a minority. In other words, we will end up either with a non-democratic Jewish State of Israel or a bi-national state in which we will have lost Zionism's most fundamental dream, in the words of Hatikvah, "to be a free people in our own land."

It is common to hear politicians say of an upcoming election, "This is the most important election in our lifetime." Fortunately or unfortunately, the next election in Israel really is, as it will likely determine whether or not Israel continues to exist as a democratic and Jewish state.

Is the threat to Israel real? I believe so. Jews are fond of noting that the modern state of Israel is the third Jewish state on this land. We lost the prior two states, the first in 586 B.C.E. after a very unwise war against Babylon, which the prophet Jeremiah had pleaded with the Jews not to enter, and the second state in 70 C.E., after the Zealots drew the Judeans into an unwinnable war against Rome.

Is there something to be learned from our prior experience? Yes. That policies that bear no relationship to reality -- such as hoping that Israel will remain a Jewish state when half or more of the people living within its borders are not Jews - will result in disaster. But it’s not too late. The next election holds the key.

S. Daniel Abraham is an American entrepreneur and founder of the Center for Middle East Peace in Washington. Follow the Center on Twitter.