Danger Beneath the Sea (2001)

Commander Miles Sheffield is a rising star in the US Navy, patronized by Admiral Eugene Justice, to the silent envy of many, including his XO and Chief on his first command mission aboard a nuclear submarine, the Lansing. This maiden voyage also turns out to be the ultimate challenge: a failed Korean nuclear missile causes a disastrous explosion which knocks his means of communications out of order, so he fears to be incommunicado in a nuclear war against an unknown enemy. Now his rivals believe his inexperience and unwillingness to man battle stations amount to desertion in war time, and plan a mutiny: they have the doctor skip him for necessary iodine shots so he'll be too sick to resist when the XO seizes command- his loyal supporters must get it back fast, for even the admiral sees no alternative then have the nearby Mako hunt them down to eliminate them before they start World War III...