New Delhi, May 26 -- When landlocked Afghanistan and neighboring Pakistan started fighting late last year and their border crossings closed, Afghans turned to their western neighbor, Iran, for an alternate to Pakistan's major shipping hub of Karachi.

They rerouted shipments through Iran's port of Bandar Abbas, but not for long. The port lies on the Strait of Hormuz, where war has stranded hundreds of ships and thousands of their crew. Meanwhile, thousands of Afghanistan-bound containers were stuck in Pakistan.

For Afghan businesses and aid groups, losing both trade routes has been devastating.

Malnourished women and children turned away

The United Nations' World Food Program, whose Afghan operations include life-saving nutritional sup...