By dawn's early light / David Hagberg.

Enhanced descriptions from Syndetics:

From the "USA Today" bestselling author of "Joshua's Hammer "and "High Flight"
On the Bay of Bengal a civilian research vessel witnesses a submarine fire a laser into the sky. Before they can process what they see, the sub blasts them out of the water and captures the lone survivor.
Immediately, one of the United States spy satellites becomes inoperative, and seemingly disappears. With the United States blind, Pakistan plans to announce their presence as a nuclear threat with an attack on India that would leave millions dead.
The only witnesses to the plan, and the only ones to know that the bomb is small enough to be dropped from an aircraft, are a CIA insertion team, headed by the President's own brother, former Navy SEAL lieutenant Scott Hanson. Their knowledge may prevent a nuclear holocaust, but they've been captured and tortured.
Thrust into the action is Commander Frank Dillon, Jr., commanding officer on the American nuclear sub "Seawolf," together with a team of SEALs. Their mission is to get them back safely. But with the world on the brink of war, getting out may be the greatest challenge of all.