Magic.
Your blockade appears to have worked. When you declare war, we will be prepared with our mass armies of birds, cyclones, and ponies equipped with talons, Mother Nature's power, and magical epicalness to create peace in the world. We have also defended our cities with dense forests of sequoia.
I'll invest in 10 tech, and stockpile the rest of the resources.
Edit: Map fixed. I was too crazy with the hamlets.