I don't think this is strategic intent as you're reading it. There's a world market and world price for oil. The US dips into their strategic reserve when prices get too high. This isn't consistent with "hoarding" oil in Alaska. It's environmental concerns that hold off on drilling in Alaska. Similarly, the issues with Shale isn't hoarding, it's environmental. In general it's citizen groups pushing back against drilling (Alaska or Shale) not on the US government.