On 10 June 1940, Italian dictator Benito Mussolini declared war. Immediately Wilson's forces invaded Libya. However, their advance was reversed when on 17 June France sought an armistice and the Italians were able to move their forces from the Tunisian border in the West and reinforce with 4 divisions those that opposed Wilson in the East. The Italian forces invaded Egypt in September 1940, and advanced some to occupy Sidi Barrani. Wilson was facing very superior forces. He had 31,000 troops to the Italians' 80,000, 120 tanks against 275, and 120 artillery pieces against 250. He realised that the situation was one where the traditional text books would not provide a solution. As with other 1940s commanders he had been well-schooled in strategy, and in thorough secrecy; he planned to disrupt the advance of the superior forces by attacking their extended lines at the right spots. After a conference with Eden and Wavell in October and rejecting Wavell's suggestion for a two-pronged attack, Wilson launched Operation Compass on 7 December 1940. The strategy was outstandingly successful and very quickly the Italian forces were cut in half.