country with id 12 has no armies, you have an airlift card, and you will not get an error if you enter "airlift 12 19 2". The result of executing the order is that the country with id 19 is not affected, and the airlift card is used.
the logic is correct.
enter "airlift 12 19 2" --- > an airlift order will be created.
execution will check if the source country has enough number of army
country with id 12 has no armies, you have an airlift card, and you will not get an error if you enter "airlift 12 19 2". The result of executing the order is that the country with id 19 is not affected, and the airlift card is used.