Today, too many friends and foes define Israel, and Zionism, by the Arab world's hostility. Doing so misses Israel's everyday miracles, the millions who live and learn, laugh and play, in the Middle East's only functional democracy. Doing so ignores the achievements of Zionism, a gutsy, visionary movement which rescued a shattered people by reuniting a scattered people. Doing so neglects the transformative potential of Zionism, which could inspire new generations of Israeli and Diaspora Jews to find personal redemption by redeeming their old-new communal homeland. Tragically, Zionism is embattled. Arabs have demonized Zionism as the modern bogeyman, and many have clumped Zionists, along with Americans and most Westerners, as the Great Satans. In Israel, trendy post-Zionists denigrate the state which showers them with privilege, while in the Diaspora a few Jewish anti-Zionists loudly curry favor with the Jewish state's enemies. Jews should reaffirm their faith in Zionism; the world should appreciate its many accomplishments. Zionists must not allow their enemies to define and slander the movement. No nationalism is pure, no movement is perfect, no state ideal. But today Zionism remains legitimate, inspiring, and relevant, to me and most Jews. Zionism offers an identity anchor in a world of dizzying choices - and a road map toward national renewal. A century ago, Zionism revived pride in the label "Jew"; today, Jews must revive pride in the label "Zionist." I AM a Zionist because I am a Jew - and without recognizing Judaism's national component, I cannot explain its unique character. Judaism is a world religion bound to one homeland, shaping a people whose holy days revolve around the Israeli agricultural calendar, ritualize theological concepts, and relive historic events. Only in Israel can a Jew fully live in Jewish space and by Jewish time. I am a Zionist because I share the past, present, and future of my people, the Jewish people. Our nerve endings are uniquely intertwined. When one of us suffers, we share the pain; when many of us advance communal ideals together, we - and the world - benefit. I am a Zionist because I know my history - and after being exiled from their homeland more than 1900 years ago, the defenseless, wandering Jews endured repeated persecutions from both Christians and Muslims - centuries before this anti-Semitism culminated in the Holocaust. I am a Zionist because Jews never forgot their ties to their homeland, their love for Jerusalem. Even when they established autonomous self-governing structures in Babylonia, in Europe, in North Africa, these governments in exile yearned to return home. I am a Zionist because those ideological ties nourished and were nurtured by the plucky minority of Jews who remained in the land of Israel, sustaining continued Jewish settlement throughout the exile. I am a Zionist because in modern times the promise of Emancipation and Enlightenment was a double-edged sword, often only offering acceptance for Jews in Europe after they assimilated, yet never fully respecting them if they did assimilate. I am a Zionist because in establishing the sovereign state of Israel in 1948, the Jews reconstituted in modern Western terms a relationship with a land they had been attached to for millennia, since Biblical times - just as Japan or India established modern states from ancient civilizations. I am a Zionist because in building that state, the Jews returned to history and embraced normalcy, a condition which gave them power, with all its benefits, responsibilities, and dilemmas. I am a Zionist because I celebrate Israel's existence. Like any thoughtful patriot, though I might criticize particular government policies I dislike - I do not delegitimize the state itself. I am a Zionist because I live in the real world of nation-states. I see that Zionism is no more or less "racist" than any other nationalism, be it American, Armenian, Canadian, or Czech. All express the eternal human need for some internal cohesion, some tribalism, some solidarity among some historic grouping of individuals, and not others. I am a Zionist because we have learned from North American multiculturalism that pride in one's heritage as a Jew, an Italian, a Greek, can provide essential, time-tested anchors in our me-me-me, my-my-my, more-more-more, now-now-now world. I am a Zionist because in Israel we have learned that a country without a vision is like a person without a soul; a big-tent Zionism can inculcate values, fight corruption, reaffirm national unity, and restore a sense of mission. I AM a Zionist because in our world of post-modern multi-dimensional identities, we don't have to be "either-ors", we can be "ands and buts" - a Zionist AND an American patriot; a secular Jew BUT also a Zionist. Just as some people living in Israel reject Zionism, meaning Jewish nationalism, Jews in the Diaspora can embrace it. To those who ask "How can you be a Zionist if you don't make aliya," I reply, "How will anyone make aliya without first being a Zionist?" I am a Zionist because I am a democrat. The marriage of democracy and nationalism has produced great liberal democracies, including Israel, despite its democracy being tested under severe conditions. I am a Zionist because I am an idealist. Just as a century ago, the notion of a viable, independent, sovereign Jewish state was an impossible dream - yet worth fighting for - so, too, today, the notion of a thriving, independent, sovereign Jewish state living in true peace with its neighbors appears to be an impossible dream - yet worth seeking. I am a Zionist because I am a romantic. The story of the Jews rebuilding their homeland, reclaiming the desert, renewing themselves, was one of the 20th century's greatest epics, just as the narrative of the Jews maintaining their homeland, reconciling with the Arab world, renewing themselves, and serving as a light to others, a model nation state, could be one of this century's marvels. Yes, it sometimes sounds far-fetched. But, as Theodor Herzl, the father of modern Zionism, said in an idle boast that has become a cliche: "If you will it, it is no dream." The writer is Professor of History at McGill University and the author of Why I Am A Zionist: Israel, Jewish Identity and the Challenges of Today. This is an updated version of an essay he first wrote for Independence Day in 2001.