How battlecruisers could turn trade defence into a conundrum

A problem has a solution, while a strategic conundrum makes every available response costly. If an opponent concentrated its battle fleet, British battlecruisers could attack maritime trade and coastal shipping. If it detached battleships to escort convoys, the Royal Navy could hunt the isolated escorts with stronger surface forces or position submarines against predictable convoy routes. Coastal shipping also carried domestic goods, so the danger extended beyond the loss of overseas trade. The battlecruisers did not have to sortie for their existence to reshape enemy deployments. Sea power here worked by forcing costly choices rather than by winning a gun battle.