Back in the day, as a UK based shipbroker, one of my clients was the US military. This regular job was to charter European civilian coastal vessels to lighter 'sensitive' cargo from large US military ships into small European ports. Although requiring tight schedules and suitably equipped ships, the process was usually relatively straightforward, but as the US military personnel involved rotated every 6 - 12 months, we had to teach them the process anew each time. On the most memorable occasion, the American man in charge decided that he knew better, and they didn't need our help or civilian ships at all: the US could do it all. So, they brought a US military ship all the way from the eastern mediterranean to Europe (empty, of course). It got there late, and turned out to be too big to get into the small port it was intended to enter. So we ended up having to find suitably equipped civilian coastal vessels for them at short notice at great much greater expense, and the cargo delivery was delayed by some 10 days.