Any day, some 28,000 soldiers, backed up by the CIA, are expected to enter the tribal area of Waziristan along the mountainous border. The goal for this risky offensive is to oust thousands of Muslim militants who have sent suicide bombers to kill innocent Pakistanis.
The assault won't be easy, and Pakistan's long-term ability to pacify this largely lawless region is still very much in doubt. People in that area need to know the government will bring a new measure of justice and prosperity.
But the apparent determination of Pakistan's military to conduct the offensive should remind the US that other countries look to it for leadership in the long fight against jihadists everywhere. And both Pakistan and Afghanistan – or "Afpak" – are the front lines in that struggle.
Congress recognized this mutual struggle last week by passing a five-year, $7.5 billion aid package for Pakistan. It should now show the same courage in further backing Afghanistan's efforts to suppress the Taliban and achieve stability. The leading US general there, Stanley McChrystal, has submitted a request to Mr. Obama for up to 40,000 additional US troops to support his counterinsurgency approach, which is focused on building up Afghan forces.
With Pakistan's new enthusiasm to curb the Taliban – and perhaps also attack Al Qaeda's strongholds – the US is in a historic position to achieve a similar measure of success there that the 2007 "surge" in Iraq achieved. Whether 40,000 more troops are needed in Afghanistan depends on Mr. Obama's expected measures of success. But Washington cannot look like an unreliable partner to Pakistan by taking a minimalist approach.
Both the US and Pakistan have had significant victories over militants in recent months. A few top Taliban leaders in Pakistan have been killed, and Pakistan's Army largely cleared the Swat Valley of the Taliban. Some of this success is due to Pakistan's new commitment to democracy under President Asif Ali Zardari, its growing ability at counterinsurgency, and rising hopes for better economic growth.
Such momentum could be lost if Pakistan perceives the US wavering in its commitment to Afghanistan.