How would the First World War change if the Netherlands and Belgium remained one country?
Short answerThe result depends on invasion success: Germany gains valuable ports, or flooding blocks it and creates a much harder front.
NotesBritain would still be expected to intervene against a German invasion of the united country. If Germany succeeded, it could gain North Sea ports that would cause serious concern in Britain. Dutch defensive flooding offers the alternative outcome: inundated ground could obstruct the invading forces. In that version of the scenario, Germany would face a front extending toward or into its own territory. The outcome remains conditional on how the invasion and flooding developed.