Answer:
No country can do everything! Every country relies on trade to get what they need! Usually, countries produce goods and services that they can provide most efficiently.
Step-by-step explanation:
Imagine that you can make cupcakes very well, maybe you can't do math. What if the person who can do math wants one of your cupcakes? You'd probably give them a cupcake for help on your math. Trading. Boom. You both get what you wanted fast and efficiently.
We're using cupcakes and math in this situation, but in SW Asian people aren't probably looking for cupcakes or math help, are they? It's important that countries help each other for their benefits, countries need other things to survive other then what they make! With specialization it makes everything quicker and easier!