If it is impossible to buy friends, why does the US send so much tax-payer money to other countries?

“Clinton did not detail the enhanced assistance but noted the United States currently has a three-year, $121 million development and economic aid program with Yemen. Separately, the U.S. administration is providing nearly $70 million in military aid this year.” (Fox News) It seems with today’s technology, we should be able to directly vote on expenditures [...]