Time – In a contested maritime century, we should start thinking about navies as the ultimate national security insurance policy. Like any insurance, they demand regular investments against risks that are unlikely but potentially grave. Navies work best to deter would-be aggression, but the industrial base to generate their capabilities underwrites military credibility. Crucially, when all else fails, that credibility stands to make certain that in the hour of need, the hardest challenges will be met and overcome.