In the period leading up to the war, Borduria had been in the midst of a devastating economic crisis and civil unrest against the military government that had been governing the country since 1919. In December 1938 there was a further change in the Bordurian military regime bringing to office a new premier, General Schtoz. Schtoz was the main architect and supporter of a military solution for the long-standing claim over Syldavia, calculating that the Kingdom would be unable to withstand a Bordurian invasion. In doing so the government hoped a military victory would reap the benefits of Bordurians' long-standing patriotic feelings towards the region and thus divert public attention from the country's chronic economic problems, and also bolster the regimes legitimacy.
The ongoing tension between the two countries increased between 19 and 25 March when several Bordurian border police stations along the Syldavian border region of Polishov were attacked by members of Borduria's secretive ZZRK posing as Syldavian soldiers. The posts were burned to the ground and Syldavian flags raised over them, an act that would later be seen as the first offensive action in the war. The Bordurian military, noting that Syldavia was attempting to reinforce its forces in the Polishov region, ordered the invasion of Syldavia to be brought forward to 2 April. General Schtoz an ardent nationalist and sylda-phobe, was the driving force in the decision to invade.
Syldavia was initially taken by surprise by the Bordurian attack on their eastern border despite repeated warnings by officials in the region regarding a military build up across the border.