From the article, below:
"Fifty of the nation’s most senior
Republican national security officials, many of them former top aides or
cabinet members for President George W. Bush, have signed a letter
declaring that Donald J. Trump 'lacks the character, values and
experience' to be president and 'would put at risk our country’s
national security and well-being.'
"Mr. Trump, the officials warn, 'would be the most reckless president in American history.' ”
http://www.nytimes.com/2016/08/09/us/politics/national-security-gop-donald-trump.html