Italy remained closely aligned with Germany despite resentment over the infamous non-aggression pact with Russia and the Assistance that Germany provided Russia in Finland. In face-to-face discussions between Mussolini and Hitler, the former informed the latter that Italy could not commit to a prolonged war but would assist Germany once Germany's western offensive proved successful; and Italy could only commit to that with three of four months of lead time.

Hitler made sure to court Mussolini further by providing updates throughout his progress in the Nazi conquest of Denmark and Norway and Mussolini decided that Italy would enter the war once Germany had achieved...

(1995). A World at Arms: A Global History of World War II.
Cambridge University Press: Cambridge, UK.

Weinberg, Gerhard L. (1995). A World at Arms: A Global History of World War II. p.123.

Ibid.

Ibid. p. 124

Ibid. p. 132

Weinberg, Gerhard L. (1995). A World at Arms: A Global History of World War II. p. 132

Ibid.