why do the AI seem so relentless attacking your civilization in just moderate difficulty

ive played AoM for about 25 hours now and first played on easy -- which was obviously too easy -- and then I went to moderate and the whole game ramped up. the AI would attack multiple times at multiple areas non stop and would more often then not destroy my AI teammate in a flash

am I too focused on resources early game and not focused on enough military strength? what are your thoughts?