In the arenas of print and politics, defending and strengthening the godly Commonwealth was an ongoing process, one that extended beyond domestic borders. The trial and execution of Charles I brought Irish and Scottish condemnations of the English parliament, and both nations denounced the formation of the republic and proclaimed Charles II king. In January 1649 the Irish Confederate Catholics concluded a treaty, known as the Second Ormond Peace, with the King's representatives in Ireland. Royalist and Irish Catholic (and for a time, some Ulster Scottish) troops subsequently undertook to consolidate their hold on Ireland in Charles II's name. The republic's response was the Cromwellian invasion of Ireland in the summer of 1649. The trajectory of Catholic and royalist fortunes changed rapidly, particularly following the Cromwellian massacres at Drogheda and Wexford in September and October 1649. By early 1651 much of Ireland lay in English hands, the royalist war effort had faded and Charles II's alliance with Irish Catholics had fractured.

During the Irish war, republican journalists, pamphleteers, politicians and military officials reminded audiences that Cromwell's army was fighting a familiar enemy: the Irish papists responsible for the slaughter of Protestants in the 1641 Rebellion. Further, their alliance with Charles II, granted in exchange for concessions to Catholics, and their willingness to take up arms against the republic demonstrated that, if left unchecked, Irish papists jeopardized the security of the Commonwealth. The subjugation of Ireland thus was vital to the defence of the godly republic. It was also cast as an act, divinely guided and sanctioned, of revenge against the 1641 rebels. Media accounts promoted English victories as evidence of providence. In September 1649, for example, when the town of Drogheda refused to surrender, Cromwell sanctioned the massacre of its inhabitants. Perfect Diurnall declared that ‘God hath gloriously owned our Army againe’. ‘This is a righteous Judgement of God’, Cromwell announced in a letter that was put into print, ‘upon these Barbarous wretches, who have imbrued their hands in so much innocent blood’.