【案例分析题】

For the first time，George Bush has acknowledged the existence of secret CIA prisons around the world，where key terrorist suspects—100in all，officials say—have been interrogated with ’an alternative set of procedures’.Fourteen of the suspects，including the alleged mastermind of the September 11th attacks，were transferred on Monday to the American naval base at Guantánamo Bay in Cuba，where some will face trial for war crimes before special military commissions.
Many of these men—as Mr.Bush confirmed in a televised speech at the White House on September 6th—are al-Qaeda operatives or Taliban fighters who had sought to withhold information that could ’save American lives’.’In these cases，it has been necessary to move these individuals to an environment where they can be held secretly （and）questioned by experts，’the president said.He declined to say where they had been held or why they had not simply been sent straight to Guantánamo，as some 770other suspected terrorists have been.
Mr.Bush also refused to reveal what interrogation methods had been used，saying only that，though ’tough’，they had been ’safe and lawful and necessary’.Many believe that the main purpose of the CIA’s prisons was to hide from prying eyes the torture and other cruel or degrading treatment used to extract information from prisoners.But Mr.Bush insisted that America did not torture ：’It’s against our laws，and it’s against our values.I have not authorised it—and I will not authorise it.’
The Pentagon this week issued its long-awaited new Army Field Manual，forbidding all forms of torture and degrading treatment of prisoners by army personnel—though not the CIA.For the first time，it specifically bans forced nakedness，hooding，the use of dogs，sexual humiliation and ’waterboarding’（simulated drowning ）—all practices that have been used at Guantámamo and Abu Ghraib.
So why did the president decide now to reveal the CIA’s secret programme？Partly，he confessed，because of the Supreme Court’s recent ruling that minimum protections under the Geneva Conventions applied to all military prisoners，no matter where they were.This has put American agents at risk of prosecution for war crimes.Mr.Bush has now asked Congress to ban suspected terrorists from suing American personnel in federal courts.

In terms of literary device, the phrase “an alternative set of procedures” in the first paragraph of the text is a kind of（）.