Energy independence is directly related to our national security.  We should explore any and all resources that are practical and economically viable (i.e.: can be sustained in the free market without artificial government support/subsidies).  Offshore and onshore drilling, building new refineries, nuclear, natural gas, clean coal, wind, hydroelectric, solar, bio-based sources (and those still being developed) should all be explored in an aggressive, yet measured and responsible manner.  With respect to the environment, we should take the steps necessary to ensure that we are not exploring any of the aforementioned options in a reckless or irresponsible way that would result in substantive harm to our environment.