Republican Senators on Tuesday voted to block a United Nations treaty that would have helped to protect disabled Americans -- including veterans -- while they are in foreign countries.

Thirty-eight Republicans voted no, giving them five votes more than necessary to defeat the United Nations Convention on the Rights of Persons with Disabilities treaty, 61 to 38.

At an event with former Sen. Rick Santorum (R-PA) late last month, Sen. Mike Lee (R-UT) announced that 36 Republicans had signed a letter pledging to vote against the treaty.

Lee told Senators on Tuesday that the treaty "threatens the right of parents to raise their children with the constant looming threat of state interference."

"We all want to support the best interest of the the child, every child," Lee said in a speech on the Senate floor. "But I and many of my constituents, including those who home school their children or send their children to private or religious schools, have justifiable doubts that a foreign U.N. body, a committee operating out of Geneva, Switzerland should decide what is in the best interest of the child at home with his or her parents in Utah or in any other state in our great union."

Writing for World Net Daily on Monday, Santorum said the treaty had "darker and more troubling implications" and suggested that it would have meant the forced abortion his daughter because she has a rare genetic disorder.

“In the case of our 4-year-old daughter, Bella, who has Trisomy 18, a condition that the medical literature says is ‘incompatible with life,’ would her ‘best interest’ be that she be allowed to die?” he asked. “Some would undoubtedly say so.”

Conservative activist Phyllis Schlafly also warned in November that proponents were "using this treaty as an opportunity to promote their abortion agenda."

Sen. John McCain (R-AZ), who suffered disabilities while fighting in Vietnam, insisted that that the treaty would have no effect on abortion laws in the United States.

"With respect to abortion, this is a disabilities treaty and has nothing to do with abortion," McCain told his Republican colleagues in a Monday speech on the Senate floor. “Trying to turn this into an abortion debate is bad politics and just wrong.”

President George W. Bush's administration completed negotiations of the treaty in 2006 and it was signed by President Barack Obama in 2009. It had been supported by veterans groups, the disabilities community and the business community.

A Yale University Study released earlier this year found that the majority of homeless veterans suffered from PTSD or other mood disorders.