But Carol Tapanila's life in Canada has tested that redefinition.
Six years after Tapanila's husband lost his job at a Boeing factory in Washington state and they moved to Canada for work, the couple became citizens of their new country. She says U.S. consular officials told her that, by swearing allegiance to Canada, she might well have lost her American citizenship.
After retiring from a job as an administrative assistant at an oil company in Calgary, Tapanila began putting $125 a month into a special savings account for her developmentally disabled son, matched by the Canadian government. In her will, she authorized creation of a trust fund to draw on retirement savings and other assets to provide for her son, who is now 40, after her death.
Tapanila says she didn't know she was required to file U.S. tax returns until 2007, when her daughter raised the subject. Her troubles were compounded by her decision to apply for a U.S. passport after a border officer told her she should have one. She has since spent $42,000 on fees for lawyers and accountants and paid about $2,000 in U.S. taxes, including on funds in her son's disability savings account.
In 2012 she turned in the passport, renouncing U.S. citizenship to protect money saved for her retirement and her son. Tapanila, 70, has tried and failed to renounce U.S. citizenship on his behalf, saying officials told her such a decision must be made by the individual alone.
"You know, we are not rich people and we are not tax evaders and we are not traitors and I'm more than tired of being labeled that way," Tapanila says.
"I'm sorry that I've given my son this burden and I can do nothing about it ... I thought we had some rights to go wherever we wanted to go and some choices we could make in our lives. I thought that was democracy. Apparently, I've got it all wrong."
AP writer Peter Enav in Taipei contributed to this report. Adam Geller can be reached at email@example.com. Follow him on Twitter at https://twitter.com/adgeller .