My family and I returned from England on January 2, midway through the second year of our extended Israel adventure. The seventh day of war against Hamas's rockets added frissons of anxiety to the usual arrival chaos. After an impromptu security check as we deplaned, guards detained one passenger. Our driver met us, saying, "The situation is rough." I told my daughter, "We're going to have to be extra careful wandering around for now." With a 13-year-old's defiant logic, she replied "Then why are we here?" It was a fair question. We were returning from Limmud - a festival of Jewish learning with 900 sessions for 2,000 participants in five days at a bucolic (if freezing) English campus. In that British bubble, or our usual Canadian cocoon, we never worried about suspicious objects or avoided riding on buses. I gave my daughter a 5:30 a.m. airport answer: "Because good people don't cut and run when bad guys start bombing." Of course, the answer goes deeper. WE ARE here because the Jewish people have only one homeland, only one Jewish place running on Jewish time, where we belong as a people and are not living by anyone else's good graces. There is nothing like Jerusalem on a Shabbat, on Succot, on Yom Kippur. The tranquility, spirituality, community and history enveloping us and enriching our lives here are unique. We are here because daily life here is also special. Kids roam comfortably, under neighbors' watchful, even prying, eyes, as adults build this small, still fledgling state, with such potential, and yes, much room for improvement. Many of those Israeli traits that Westerners dislike, the pushiness, the incessant improvisations, are the very characteristics that will help win this war and make this experiment work. We are here because we like Jerusalem's many "meaning junkies," as one friend calls them, seeking more to life than the latest pop culture trends, hoping to root our lives in enduring values. We are here because when we wander around Jerusalem's Old City or delight in Tel Aviv's modernity, when we remove ancient pots from the ground or buy modern artistic knickknacks, we do it with the heroes of Jewish history sitting proudly on our shoulders: Deborah the prophetess or David the king, Sarah Aaronsohn the Nili spy or Menachem Begin the fighter turned peacemaker, Golda Meir the prime minister who also left America's comforts or David Ben-Gurion, the prime minister who knew when to compromise in accepting the UN partition plan and when to plunge ahead in declaring the state despite American and Jewish calls to wait. We are here because our great-grandparents dreamed of being here but could not be, because one grandfather fought in the 1948 War of Independence, and another helped smuggle weapons from New York so Israel could be free. For generations Jews have been singing "Next Year in Jerusalem." This is our time to be in Jerusalem, build Jerusalem and be rebuilt by Jerusalem, not sing about it as if it were some impossible dream. We are here because the fight against terror knows no boundaries; this month it is Sderot and our cousins' kibbutz in the Negev, last month it was Mumbai, seven years ago on 9/11 it was my hometown New York. But here Jews control their own fate, unlike the Lubavitchers in Mumbai who had to wait for the Indian army to get organized, unlike in Montreal where we have to beg to designate firebombing a Jewish day school a hate crime, only to see the perpetrators punished lightly. WE ARE here because - as I said at the airport - good people cannot flee but must fight evil. Even critics condemning Israel's supposedly "disproportionate response" implicitly concede that a state is justified in responding to 10,000 rockets terrorizing its citizens over eight years. And I for one, am proud of Israel's response - only after years of exhausting diplomatic efforts, only after offering the Palestinians a chance to build Gaza by removing the constant struggle with the settlers and the army, only after naÃ¯ve but well-meaning American Jewish philanthropists raised $14 million to donate the burgeoning hothouses the Israelis developed, inviting Palestinians to make Gaza productive rather than a terror center - which Palestinians then trashed. I am proud of Israel's attempt to minimize civilian casualties even as Hamas terrorists cower behind women and children, behind mosques, hospitals and UN schools. We are here because if we flee, who are we; if we let others fight for us, what are we; and if none of us fight, where will we - and the world - be? What values would we stand for if we abandoned Jerusalem, as cousin Daniel continues farming on the Gaza border with rockets flying overhead, as our friend Mickey and thousands of others serve their country, the Jewish people and the civilized world so honorably and selflessly? Israel, the Jewish people's national project, is a rich tapestry. Every day those of us in Israel, temporarily or permanently, add golden threads to this extraordinary old-new artwork. Some threads may be as short as the ones birthright israel participants add in their 10-day stints here, some may only last a year or two, others are lifelong. Others, tragically, are cut short - as we have seen too frequently in this war as well. This is our moment to spin our Israeli yarn, and add to this magical Jewish tapestry with as many golden cords as we can create for as long as we choose, on our timetable, not cowed by anyone's threats. And yes, being here will sometimes test our fiber. But a good yarn also means a great story, and we are blessed to be here, now, weaving the tapestry of modern Israel - and helping to star in this grand narrative, one of the amazing adventures of 21st century modern democratic life. 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 and Leading from the Center: Why Moderates Make the Best Presidents.