Why was President Trump's first foreign trip as U.S. President to Saudi Arabia the US' largest foreign military sales customer.?

President Trump made Saudi Arabia into an ally of the US. He also set off many reforms in that nation including reforms for women. And, he did it without having to bow to their little king like Obama did.

Trump visited Belgium, Israel, Italy, Saudi Arabia, and Vatican City during his first international trip as President.

Would it be to secure continued sales, thereby protecting America's interests overseas and jobs in the US?