Originally Posted by cherokeesam
Sorry, but that's a total misinterpretation of the relationship of Loki to Thanos in Avengers. The Other refers to Loki as an "ally," not a slave. The Other tells Loki he can have "his" (Loki's) war --- it's not a war that Thanos planned.
Loki came up with the plan to conquer Earth on his own, and he *asked* Thanos for the Chitauri, using the Cube as a bargaining chip. As far as Loki is concerned, they negotiated as equals; as far as Thanos is concerned, Loki is just some happy cosmic accident who stumbled onto his doorstep and might prove useful in Thanos' designs on Asgard --- but he is unworthy of Thanos' direct attention, so all the negotiations are handled by proxy through The Other.
I never got the impression at all that Loki and Thanos are equals. Loki was putting a brave face on for The Other, but at the end of their meeting he was sent away in with a painful reminder of the horrors to come should he fail Thanos. And fail he did.
The very fact that Thanos did not deign to dirty his hands with Loki shows that their relationship was one of quite unequal power, no matter how much bravado Loki tried to show when talking to The Other. He may have hatched the plan to conquer Earth, but without Thanos he would never even have been able to come here, much less cause mayhem. Yes, The Other called Loki an "ally," but he was treated like a servant, given orders, threatened and not even allowed near his master's feet to plead his own case. Loki was only tolerated because he was of use to Thanos. And he was quite obviously afraid of the consequences of failure.
Consider the terms of the bargain, as well. Loki was given an army to conquer Earth and claim its imaginary throne, but in return he was going to give Thanos an object that would allow the Titan to rule the entire universe. That was the sort of deal only a fool or someone with pathetically limited vision would enter into. Thanos probably trusted that Loki lacked the wit and insight to realize that the Tesseract could give him ultimate power over all reality, not just the Earth. Loki had the mindset of a lackey, of an inferior, so it was safe for Thanos to use him as a pawn in his plans.