President Barack Obama began overhauling U.S. treatment of terror suspects Thursday, signing orders to close the Guantanamo Bay detention center, shut down secret overseas CIA prisons, review military war crimes trials and ban the harshest interrogation methods.

With his action, Obama started changing how the United States prosecutes and questions al-Qaida, Taliban or other foreign fighters who pose a threat to Americans — and overhauling America’s image abroad, battered by accusations of the use of torture and the indefinite detention of suspects at the Guantanamo prison in Cuba.

The centerpiece order would close the much-maligned Guantanamo facility within a year, a complicated process with many unanswered questions that was nonetheless a key campaign promise of Obama’s. The administration already has suspended trials for terrorist suspects at Guantanamo for 120 days pending a review of the military tribunals.

In the other actions, Obama:

_Created a task force to recommend policies on handling terror suspects who are detained in the future. Specifically, the group would look at where those detainees should be housed since Guantanamo is closing.

_Required all U.S. personnel to follow the U.S. Army Field Manual while interrogating detainees. The manual explicitly prohibits threats, coercion, physical abuse and waterboarding, a technique that creates the sensation of drowning and has been termed a form of torture by critics. However, a Capitol Hill aide says that the administration also is planning a study of more aggressive interrogation methods that could be added to the Army manual — which would create a significant loophole to Obama’s action Thursday.

A task force will study whether other interrogation guidelines — beyond what’s spelled out in the Army manual — are necessary for intelligence professionals in dealing with terror suspects.