Tom Clancy Act of DefiancePre order the pulse racing new Jack Ryan thriller, Tom Clancy Defense Protocol, now! ________________ For Jack Ryan, the greatest threat lurks beneath the waves . . . again. US intelligence is reporting turmoil in the Russian navy. Their deadliest submarine, the Belgorod, has unexpectedly launched. Who authorised the departure? What mission is it on? And, most disturbing of all, what weapons do the giant doors on the sub's bow hide? It's been four