What did the gulf of tonkin resolution allow president johnson to do and how did this break the system of checks and balances?

The Gulf of Tonkin Resolution allowed President Johnson to send troops to Vietnam, thus waging a war without actually "declaring" it as war. Checks and balances keep the power divided and balanced among government branches; it is the duty of Congress to declare war, so President Johnson waging war without the declaration of war by Congress breaks this system. 

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