 Some goods lack weight in ad bellum proportionality, not because they are lexically inferior to other values at stake, but because they are conditional in particular ways. Soldiers have conditional obligations to fulfil their roles, grounded in their contracts, oaths, and their co-citizens’ legitimate expectations. That carrying out an operation fulfils my oath gives me a reason to perform that operation, which has to be weighed in the proportionality calculation (Lazar 2015b). But these reasons cannot contribute to ad bellum proportionality in the same way, because they are conditional on the war as a whole being fought. Political leaders cannot plausibly say: “were it not for all the oaths that would be fulfilled by fighting, this war would be disproportionate”. This is because fighting counts as fulfilling those oaths only if the political leader decides to take her armed forces to war.