WASHINGTON -- Warren Weinstein made his Pakistani friends nervous when he first arrived in their country in 2004. The trouble wasn't that the veteran American development expert, then in his early 60s and working as a contractor for the U.S. Agency for International Development, seemed unable to fit in, or unprepared to handle the dangers of an increasingly volatile Islamic republic. It was that he was a little too enthusiastic in his embrace of Pakistan. "He would eat so much [spicy food] you cannot even imagine," said Shahab Khawaja, then a top bureaucrat running the government program Warren was advising.