Most Americans would tell you that if you're a US citizen, then your children will automatically be US citizens. Most Americans would be wrong. That's what Yonit Tsadok found out when she took her infant son to the American Embassy in Tel Aviv to get him a US passport. To her shock, she was told that despite having been an American citizen from birth, she could not confer that citizenship on Yoav, now seven months old. "I was completely, 100-percent sure that since I'm an American, my son is entitled to American citizenship automatically," she said over the phone from Ramat Gan, while Yoav gurgled in the background. "It was just this common knowledge. It's just the way I thought the world works." It was a rude awakening more and more Americans might be subjected to as they make aliya without realizing that bringing their children to Israel jeopardizes their ability to pass on American citizenship. Tsadok had moved to Israel from her native Philadelphia with her family at the age of six. She went to Florida for university but decided to return after just 22 months there. Little did she know what a difference two months would make. That was the margin between her being able to pass on her status as an American or not. As Tsadok found out - once she had paid $250 and spent six hours at the embassy with a baby - to pass on citizenship, an American citizen needs to have spent at least five years living on American soil with at least two of those years after the age of 14. She was two months short. "It was very disappointing," she said. "It's always good to have American citizenship at a time of need. Living in a dangerous country as we do, it's always nice to have a ticket out." A US Citizen and Immigration Services press officer referred The Jerusalem Post to the law regulating citizenship without offering a rationale for its requirements. But the official did point out that the act allows living grandparents who meet the residency requirement to confer citizenship on grandchildren under the age of 18 in place of the parents. And there is also the possibility for parents to return to the US after making aliya to meet the residency requirements themselves. Washington-based immigration lawyer Leslie Dellon said the US government was interested in making sure its citizens had a deep enough connection to the country. "If you've been living most of your life abroad," she said, "the concept is there aren't the ties, the communal identity, the sense of being American. They feel it's getting attenuated." Danny Oberman, executive vice president of operations for Nefesh B'Nefesh, which helps Americans make aliya and advises them during the absorption process, said the issue that Tsadok faced hadn't been a significant concern or subject of questions from potential immigrants. With the average age of American immigrants that Nefesh B'Nefesh assists - around 3,000 for each of the last several years - at 32.5, Oberman said, "the issue of their grandchildren's citizenship is not a major issue for them." And to the extent that people are aware of the policy, he added, "The ideological dimensions for making aliya are probably more important than the American citizenship of their grandchildren." Either way, the policy itself can end up reinforcing the decision to make aliya, as it did in Tsadok's case. "It makes me feel a little less welcome," she said of her attitude now toward the country of her birth. "I've always felt that America was a second home to me, and now I'm pretty much sure that Israel is my main home."