The effectiveness of NATO conditionality for institutional reforms is highly controversial. Some papers argue that any effect this conditionality might have had may be due to endogeneity effects, i.e. NATO may have picked the winners. We argue that this is not the case. This is supported by econometric evidence based on panel data. An event study reveals that entry into NATO’s accession process was mainly driven by neighbourhood and good relations with the West. We conclude that empirical evidence clearly supports a stronger role of NATO’s political agenda, i.e., low entry barriers but strict accession conditionality.