Washington's best chance to deter Pakistan from proceeding with its nuclear tests probably lay in offering ironclad security guarantees. In today's national mood, however, neither Congress nor the administration would be likely to support such a guarantee. And the history of US-Pakistan relations shows how difficult it has been to sustain even a vague US commitment.
Pakistan has, from its beginning, feared for its security. Few in the new country believed that India had abandoned the goal of reuniting the two halves of British India. China loomed as a potential threat to the north. Afghanistan to the west had historically been an invasion route to the subcontinent.
Pakistan initially looked to the US for security assistance. But from Islamabad's perspective, the experience has been discouraging. Four times during the past 33 years, at critical moments in Pakistan's history, Washington has unilaterally suspended military help. In May of this year, after Pakistan exploded five nuclear devices, all assistance was again cut.
After the subcontinent's independence in 1947, governments in Washington and Karachi (then the capital) built a relationship that implied US concern for Pakistan's security. The US commenced a program of military sales in May 1954. Pakistan joined two Western-sponsored alliances, the South East Asia Treaty Organization and the Baghdad Pact (later the Central Treaty Organization). In 1959, these alliances were supplemented by a bilateral security agreement.
These arrangements, however, were built on illusions. The US saw Pakistan as a part of the "northern tier" encirclement of the Soviet Union. Pakistan perceived its new ties to Washington as bolstering its strength vis-a-vis India. But Washington's commitments were weak. The US itself never joined the Baghdad Pact.
When India and China fought a border war in 1962, Washington, alarmed at the prospect of Chinese advances, rushed military assistance to India, to Pakistan's dismay.
Two years later, Pakistan launched a war against India, hoping to regain disputed Kashmir. Because Washington considered Pakistan had illegally used US equipment, military supplies were embargoed. Pakistan for the first time turned to China for help; China later helped Islamabad develop its nuclear program.