The union proposal behind the diplomatic breakdown

The naval confrontation sits beside a much larger diplomatic proposal: a close union or confederation between the English Commonwealth and the United Provinces. Such an arrangement could have joined Dutch maritime power to the New Model Army and dramatically altered the balance against France and other European states. Dutch leaders instead saw the danger that Oliver Cromwell and his military system might dominate the partnership. London was also angered that Dutch merchants continued supplying Royalist colonies despite Commonwealth requests to stop. Cromwell and the Rump Parliament initially expected fellow Calvinist republicans to act from shared ideology, then had to learn that state interests did not follow religious fraternity. Shared Protestant and republican language failed to produce trust, while Dutch naval expansion looked threatening in London rather than reassuring.