Economics is not as simple as addition and subtraction .
If a country is taken as a system then this system can never give(export) less than what it takes(import) from outside world ..
System has to give something equivalent back to the outside world from where it takes the needful ..
Theoritically imports always equal to the export ..
then question arises if a system imports 100$ of goods and exports 50$ worth goods ,what is exactly happening to the system ?..
How can the system pay back remaining 50 $ of service it recieved from outside world ?
System starts to give a power(money) to the outside world so that they can get their remaining 50$ worth service inside system or in future ..
How does this phenomenon will affect health of system ?
Having taken the resources system will strengthen itself and outside world will have a say or power or share in that system