A key aspect of the play is the opposition of Scotland and Italy during World War Two. During the war, the Italian community in Scotland faced hostility, internment and even deportation.
Shortly afterwards, Italian immigrant men over the age of 16 were declared "enemy aliens". Over 4,000 Italians were arrested, just as happens to Massimo. Many were shipped to internment camps on the Isle of Man, others were transported to Canada or Australia.
On 30 June 1940, the cruise ship SS Arandora Star was torpedoed while transporting Italian and German "enemy aliens" to Canada. Of 734 Italians on board, 486 died. Act 1 Scene 14 sets up that Massimo's father was one of those on board.
There were anti-Italian riots in cities including Edinburgh and Glasgow. Italian businesses were attacked. This explains why the Scottish mob attack the Pedreschi's shop in the play.
The war ended in 1945. The aftermath of the war is evident in Act 2 Scene 1 when Luigi describes the destruction of Italian villages and the loss of his livelihood.