P1: Some people = opposed to compulsory national service
why? it goes against liberal principles reqd by Western democracies
But the need for National service is like the need for Taxes.
Shared sacrifice = taxes. No taxes = No Enforcement. Enforcement = Societal benefits
P2: Defending our nation is necessary, therefore govt is justified in compelling citizens to perform national service
P3: Opponents may contend that taxation and national service are like apples and oranges, and national service = too much big brother
P4: Refutes P3 -- national service and taxation are comparable, both provide benefits more than is necessary. And benefits to society provided by both are similar.
Author = Opponents should accept that "shared sacrifice" and "societal benefits" underpin national service, and is required by liberal states (author disagrees with opponents of compulsory NS)