A Double standard (n.) is a misnomer: the doctrine is really one clear standard, Adam Smith's vile maxim — everything for ourselves and nothing for anyone else.
A Double standard (n.) shows plainly when an argument for bombing farm cooperatives would, applied to an ally's settlements, be called terrorism.
A Double standard (n.) is remarkable, but less remarkable than the inability of those who hold it to see it.
A Double standard (n.) is how we read noble intentions: manifest pretense when others profess them, sincere conviction when we do.
The Double standard (n.) is enforced by vocabulary: the enemy's mass killer is 'crazed', a 'war criminal', a 'mass murderer'; the ally who killed as many is at worst 'authoritarian'.
A Double standard (n.) is sometimes confessed outright: a U.S. official explained that a hostile government's threat to U.S. security 'allows us to change our yardstick'.
Double standard (n.) shows itself in a simple swap: put the same confession in the enemy's prison, and every question the press declined to ask would ask itself.