Complex sentence: Later, in the spring of 1940, the "Kriegsmarine" became even more opposed to invading Britain after its Pyrrhic victory in Norway: after Operation Weserübung, the "Kriegsmarine" had only one heavy cruiser, two light cruisers and four destroyers available for operations.
Split into simpler sentences: Later, in the spring of 1940, the "Kriegsmarine" became even more opposed to invading Britain after its Pyrrhic victory in Norway. After Operation Weserübung, as the invasion of Norway had been code-named, the "Kriegsmarine" had only one heavy cruiser, two light cruisers and four destroyers available for operations.