On the level 1 or 2 above "normal" in a campaign game (small map, just me and the drengin), I built a few extremely basic fighters (speed 3, beam 1) as quickly as possible and sent them out to take down all the constructors and colony ships to help me win the early expansion war. Once I'd done that, I sent a single ship to each of the enemy planets as a blockade.
Then I developed at my leisure. A bit later on, I began to get a tad concerned as they were outresearching me militarily and had got a couple of insanely good production bonuses on their planets to outproduce me too. If they'd built a military fleet at that point I'd have been in a fair bit of trouble. But they didn't...they just kept on building unarmed scouts and constructors which I picked off with ease.
I don't know if this behaviour repeats at higher levels, but I don't think it should occur at ANY difficulty, let alone a notch or two above "normal".
