The US revolutionary war
unrestricted submarine warfare
Un-restricted submarine warfare
Submarine Warfare
submarine
Germany's return to unrestricted submarine warfare.
submarine warfare
1. Unrestricted Submarine Warfare 2. Sinking of several US ships
We warned them not to return to "un-restricted warfare." They did it anyway; we declared war.
The Sussex Pledge
Unrestricted submarine warfare (in the Atlantic).
Germany's unrestricted submarine warfare