Pace ac bello merita

Although it is often claimed to mean 'Service in peace and war', actually it should translate as:

'peace and also war are just' (are right, deserved, of value etc.)

For 'merita' to translate as 'good service' it would be at the start of the sentence as:

"Merita in pace ac bello"

in a similar manner to 'requiescat in pace'