>> reporter: under cover of darkness, three air force cargo jets, escorted by f-18s, dropped pallets like these, loaded with thousands of gallons of water and meals ready to eat. >> with the isis threat out there, our crews will be in some danger by doing these airdrops. >> reporter: those isis terrorists taking control of iraq have surface-to-air missiles and a slew of firepower. they're threatening to take control of the largest electric dam in the country and are closing in on erbil. the kurdish capital has key american outposts with hundreds of military consultants and a consulate. >> i've directed our military to take targeted strikes against isil convoys should they move toward the city. >> reporter: the strikes have not yet begun but u.s. commanders have a green light. >> if we go into air strikes, we're opening another chapter on a book the white house had hoped they had closed. >> reporter: the last u.s. troops pulled out of iraq in december 2011. president obama says he does not plan to send combat troops back in.