Ideology traits make for negative relations.
Think US/UK and Russia in WWII and after. You may have an enemy of my enemy is my friend. That doesn't mean you like them. Patton was in favor of immediately attacking Russia at the end of WWII. MacArthur was in favor of using nukes when the Chinese backed North Korea and through us back to the 38th parallel.
While I think this is a simplistic (dare I say gimicky?) thing. It has parallels.
It is really shocking the more I study history that the "regular" citizen is so uninformed. They listen to sound bites. Nazi Germany really was the leader in modern propaganda and most people are sheep. I am not talking about people on this forum by and large. Just look at any comment thread almost anywhere and it will frighten you on the level of ignorance and hatred.
Hell, in the 80's I had classmates that noticed my name was "German" (actually it was from the Alsace-Lorraine border, but never mind) so my family must have been Nazi sympathizers! Dude, my family moved to Texas from Iowa before WWI! About 1/2 of my ancestors were Irish and British!
This is the stuff wars are made of. Small minds, bigotry and nationalism.
The US has been involved in military action more than people think. 1898 Spanish-American war, 1917-1918 WWI, 41-45 WWII, Korea, Vietnam, Grenada, Panama, El Salvador/Nicaragua, 2 times in Iraq and Afghanistan. We have had several wars with Mexico, Canada until around 1800. Then there are the lesser ones of Libya (2x, as the song goes "from the halls of Montezuma to the shores of Tripoli http://en.wikipedia.org/wiki/Marines%27_Hymn), Serbia-Croatia, now ISIS.
So you can think of the Altarians as Americans. We are peaceful, to a point. I am not trying to troll or start a fight, just giving examples. Many of those wars were justified, some not so much.