asked Her Majesty's Government:

Whether the cost of NATO operations is paid by the countries providing the military contribution to the operation concerned, or whether it is paid by all members of NATO in proportion to their gross domestic product. [HL783]

The majority of the costs of NATO operations lie with the individual nations contributing the force elements. However, certain costs (such as the command structure in theatre and critical theatre enabling capabilities) are commonly funded by all nations to an agreed formula based on gross national income.