III. "Do not swear falsely by the name of the LORD..."
This is a prohibition against making false oaths in the name of the God of Israel, specifically those which are pointless, insincere or never carried out.
I know those who have called themselves Christian, or something and swear a lot, but...
Just think,
the nautical might of the British and the power of the German land forces would have been devastating.
the Luftwaffe and the RAF were powerful on their own, but together they would have been unbeatable.
the Germans would have been fight the Russians without fighting in North Africa...