score:15
Mers-el-Kebir was indeed a tragic episode in the history of Anglo-French relations. And it wasn't the only incident of its kind (though it was by far the costliest in lives). A number of engagements made up "Operation Catapult". British sailors used force to seize various French ships, some of them, like the giant submarine Surcouf already in British ports. Several lives were lost in fighting on the Surcouf. These inglorious incidents have been somewhat ignored in standard histories of the war. Michael Portillo featured the Mers-el-Kebir incident an episode of his Radio 4 series Things We Forgot To Remember to make the point that it was just as much a turning point in Britain's prosecution of the war as was the Battle of Britain.
The difficult relationship between Britain and France after 1940 features in two recent publications: Colin Smith's England's Last War with France and Peter Mangold's Britain and the Defeated French.
In terms of its effect on international relations, let's look at Vichy France, De Gaulle's Free French, the United States and other friendly neutrals, and lastly Germany.
Relations between Britain and Vichy were of course irretrievably damaged by the incident (there was little warmth there even prior to Mers-el-Kebir). Vichy broke off diplomatic relations with London and even launched a small retaliatory raid on Gibraltar. But Vichy stopped short of declaring war on Britain, and there was never a formal state of war between Britain and France even though further bitter Anglo-French fighting occurred in Syria, West Africa and Madagascar in the following two years.
Relations with De Gaulle were more complicated. The incident was of course deeply painful for De Gaulle but he was still an obscure entity and with little option but to continue working with the British. On the one hand his efforts to recruit French soldiers and sailors to fight with him alongside the British were badly hurt. On the other, however, the lasting enmity generated between London and Vichy was helpful to him as the British were forced to back him unreservedly (the Americans persisted much longer with their policy of ignoring De Gaulle and courting Vichy).
But for Britain the truly important audience for her actions was in Washington. Mers-el-Kebir was undertaken for two reasons; to eliminate any risk at all that Germany would use French ships to challenge British naval dominance in the Mediterranean and to demonstrate to the Americans her resolve to stay the course of the war. A Britain considering some kind of accommodation with Germany would certainly not have killed and maimed thousands of sailors belonging to a recent friend. Mers-el-Kebir is linked by many historians to Roosevelt's decision to go ahead with the destroyer deal, since the president could now be confident that the ships wouldn't easily fall into German hands.
To a certain extent Germany received and understood Catapult's message in the same way. Hitler was forced to delay a planned peace overture to Britain. But with typical self-delusion Hitler continued to hope and expect Britain to come to the negotiating table. Goebbels stoked anti-British feeling in Paris distributing the famous "Remember Oran" posters featuring drowning French sailors.