KABUL, Afghanistan (CNN) -- Sen. Barack Obama arrived Saturday in Afghanistan on the first stop of his tour of the Middle East and Europe, aimed at boosting the U.S. Democratic presidential hopeful's foreign policy credentials, his campaign confirmed. The U.S. senator from Illinois also plans to visit Iraq, although details of the trip have have not been made public for security reasons. The fight in Afghanistan has become a more pressing issue on the political radar. Three times as many coalition soldiers and other military personnel have died in July in Afghanistan than in Iraq. On Sunday, nine U.S. soldiers...