The United States is now relying heavily on foreign intelligence services to capture, interrogate and detain all but the highest-level terrorist suspects seized outside the battlefields of Iraq and Afghanistan, according to current and former American government officials. Pakistan's intelligence and security services captured a Saudi suspect and a Yemeni suspect this year with the help of American intelligence and logistical support, Pakistani officials said. They are still being held by Pakistan, which has shared information from their interrogations with the United States, the official said. The current approach, which began in the last two years of the Bush administration and has gained momentum under Mr. Obama, is driven in part by court rulings and policy changes that have closed the secret prisons run by the Central Intelligence Agency, and all but ended the transfer of prisoners from outside Iraq and Afghanistan to American military prisons. Human rights advocates say that relying on foreign governments to hold and question [captives] could increase the potential for abuse at the hands of foreign interrogators. The fate of many ... whom the Bush administration sent to foreign countries remains uncertain. One suspect, Ibn al-Shaykh al-Libi, who was captured by the C.I.A. in late 2001 and sent to Libya, was recently reported to have died there in Libyan custody. In the last years of the Bush administration and now on Mr. Obama's watch, the balance has shifted toward leaving all but the most high-level terrorist suspects in foreign rather than American custody.