Between her visits to Israel every two years, and her involvement in Sag Harbor’s Jewish community, Zoe Vatash has always held a special place in her heart for the tiny Jewish state in the Middle East.Now, the 18-year-old will make it her home for the next two years, while she serves in the Israel Defense Forces—as all Israelis do when they turn 18.

“I’ve always loved Israel—it’s like a second home to me,” Ms. Vatash said last week in an email from the Kibbutz Beit Zera, where she is staying. “I believe in its right to exist, and I believe that it is my duty to serve my part in ensuring its safety.”

Ms. Vatash made Aliyah—as the immigration to Israel, a fundamental principle of Zionism, is known—earlier this month with 59 Americans and Canadians through a group called Nefesh B’Nefesh, which aims to re-energize the Aliyah process by making it easier for Jews financially, socially and professionally.

She will be living on the Kibbutz with other Americans and studying Hebrew until November or December, when she will then be transferred to a military base. She said she does not yet know where that will be: “I’m most excited to find out what I’ll be doing.”

Leah Oppenheimer, the director of the Hebrew School at Temple Adas Israel in Sag Harbor, and Ms. Vatash’s longtime teacher, explained that her pupil has always been deeply involved with the Jewish way of life. “What I think is that it is a great way to sort of affirm your belonging to the Jewish people,” Ms. Oppenheimer said of the teenager’s decision to make Aliyah and serve in the army. “After 2,000 years, I don’t have to tell you that we don’t belong.”

Ms. Vatash first came to the realization that serving in the Israeli army was a serious but doable option for her during her junior year of high school, when her friends were deciding which colleges they should apply to. Most of her family is in Israel, she said, and both of her parents, Sue Vatash and Dr. Gal Vatash, are Israeli and served in the IDF.

Recently, Ms. Vatash had photographs that she had taken during previous trips to Israel on display at Temple Adas—she raised $1,800 to use during her time at the Kibbutz.

“I love the people, I love the landscape and I love the culture,” Ms. Vatash said. “After, the plan right now is to go back to the States for college, but, honestly, I have no idea how I’ll feel in two years; only time will tell.”

“She was very excited—her soul is there,” Ms. Oppenheimer said. “I think, in a way, all of us are there with her a little bit. I spent a lot of years teaching her Israel—she carries us there.”