LAHORE, Pakistan -- Pakistan is on the brink of chaos, and Congress is in a critical position: U.S. lawmakers can hasten that fateful process, halt it or even help turn things around. The speed and conditions with which Congress provides emergency aid to Islamabad will affect the Pakistani government and army's ability and will to resist the Taliban onslaught. It will also affect America's image in Pakistan and the region. Pakistanis are looking for evidence of the long-term U.S. commitment about which President Obama has spoken.

Since Obama announced his strategic review of U.S. policy on Afghanistan and Pakistan, worsening conditions here have nudged Afghanistan from the top of his foreign policy agenda. Pakistanis are beset by a galloping Taliban insurgency in the north...