WASHINGTON — President Bush and Secretary of State Colin Powell have done everything possible to enlist Pakistan as a full ally in the war on al Qaeda and global terrorism. But Pakistan has not responded with the active support that Bush demands from every state that is "with" the United States in this conflict.

President Pervez Musharraf’s failure to match promises with sustained action undermines Bush’s campaign to make his war on terrorists a clear struggle of good vs. evil. Other nations will quickly notice the Pakistani shortfall and follow suit by mouthing deceptive words and taking evasive action.

Washington now allows Musharraf to make expediency the guiding principle of the relationship. The argument that Musharraf’s survival, and Pakistan’s interests, must take precedence for the time being over hunting down al Qaeda and halting cross-border terrorism has strong support within Powell’s State Department.

Powell swiftly and aggressively moved to manage the relationship — and Musharraf — in December when a terrorist attack on India’s Parliament pushed the Asian subcontinent’s two nuclear powers to the brink of war.

In his first success as chief U.S. diplomat, Powell harried the Pakistani general into making a forceful speech on Jan. 12 condemning Islamic extremism. Musharraf also ordered the arrest of about 2,000 people he labeled as extremists, and trumpeted that step as proof of his intentions.

But Musharraf is now managing Washington, which has turned its attention to the Israeli-Palestinian conflict, Iraq and other matters. He has steadily backed away from his January boldness even as Pakistan rakes in hundreds of millions of U.S. dollars in aid. Powell has said nothing as the backsliding has become more flagrant and more harmful to Bush’s global cause.

Pakistan has released at least 800 of those arrested in January, requiring only that they sign pledges to behave. A leader of one of the most extreme factions has been moved from prison to a comfortable government guesthouse.

When U.S. commanders in Afghanistan talked last week of going into Pakistan to find the al Qaeda and Taliban forces who that escaped from American operations earlier this month, Pakistani spokesman Maj. Amir Uppal insisted there was no need: Pakistani forces had sealed the border so efficiently that there was "no possibility" of escapees being in Pakistan.

U.S. officials know that is a lie. They also know that Pakistan has resumed helping guerrilla groups to infiltrate into Kashmir and India in recent days, despite Musharraf’s promises to Powell.

And they know that Pakistan’s cooperation in the investigation of the brutal murder of U.S. journalist Daniel Pearl has been far from complete. Pakistan’s intelligence service had custody of Sheik Omar Saeed, the chief suspect in the case, for a week before disclosing that fact to U.S. authorities — and probably to Musharraf.

Why the delay? One possible reason is that Saeed did not turn himself in but was contacting the intelligence service as part of a long-standing relationship similar to the one Pakistani intelligence had established with the Taliban, Osama bin Laden and the Kashmiri terror groups that Musharraf promises to shut down. Something triggered an arrest and a week-long pause in deciding what to do with Saeed.

The intelligence service is a house of horrors waiting to break open. Saeed has tales to tell. And that may explain a comment from Musharraf that U.S. Ambassador Wendy Chamberlin reported back to Washington: "I’d rather hang him myself" than extradite Saeed, the Pakistani president reportedly said in their conversation.

The clear instructions that Deputy Secretary of State Richard Armitage gave to a Pakistani intelligence commander soon after Sept. 11 — halt all support for terrorism or else — have, with time, faded and seemingly lost their impact. Washington is now negotiating with Musharraf, not forcing him to act.

When an American diplomat and her daughter were killed by a terrorist in a Protestant church in Islamabad on March 17, Powell did two things immediately: He ordered the departure of nonessential embassy personnel and families and had his spokesman say that "this decision doesn’t reflect any lack of confidence in Pakistan’s ability to protect Americans."

False allies are often more troublesome for America than declared enemies. The moral and diplomatic drift on Pakistan now strongly resembles the failure of the first Bush administration on Iraq in the late 1980s. Saddam Hussein’s threats to incinerate Israel and invade Kuwait were explained away by State Department experts as rhetoric. Iraq was seen as too important to confront — or even to describe its actions truthfully. The second Bush administration is on the road to making exactly the same mistake with Pakistan.

Jim Hoagland can be reached at The Washington Post Writers Group, 1150 15th St. NW, Washington, DC 20071-9200 or hoaglandj@washpost.com.