I had to laugh when I saw this vintage Valentine's card which incidentally was given by an ex WW2 commando to his beloved some time in the early 1950's
Sweet isn't it but hey, look at that knife.... here's a close up look see-->>>>>
The F–S fighting knife was made famous during World War II when issued to British Commandos, Paratroopers and the SAS especially for the 1944 Normandy landings and it's optimised design made it perfect for surprise attack and suppression fighting.
As Fairbairn stated in his seminal book published in 1942.."In close-quarters fighting there is no more deadly weapon than the knife. In choosing a knife there are two important factors to bear in mind: balance and keenness. The hilt should fit easily in your hand, and the blade should not be so heavy that it tends to drag the hilt from your fingers in a loose grip. It is essential that the blade have a sharp stabbing point and good cutting edges, because an artery torn through (as against a clean cut) tends to contract and stop the bleeding. If a main artery is cleanly severed, the wounded man will quickly lose consciousness and die.'
And so it was that the length of the F-S knife blade was optimised to be able penetrate the body after passing through the 3 in (7.6 cm) of the thickest clothing that was anticipated to be worn in the war, namely that of Soviet greatcoats.
With this sort of performance you can skewer your Valentine's ticker no problem.......... romantic eh?