Thanks for all of the replies.
To make things clear - my brother was the one who initiated the whole "dad come back to the U.S." thing. He even had it in his mind that he was going to have my father full time! But it is eminently clear that my brother did not think this through. I DO fault him for that, because it is not hard to imagine the impact an 80 year old man might have on your life.
I don't expect my brother to be a perfect caregiver. And he doesn't need to be. My father is 80 and has some relatively minor physical issues, but mentally he is all there. I have good conversations with him all the time. He keeps up with the news, facebook, etc. So he is not that far "down the hill" so to speak. He does however need someone to check in on him from time to time, to make sure he can get to the grocery store, and to get out of the house every now and then. When he was with me I made sure he had that stuff and more. Because I THOUGHT of what he would need and arranged it. I also just took the opportunity to spend time with my father, talk with him, and set my kids to climbing all over him.
In sum, I'm not asking my brother to change diapers, wipe spittle, and administer drugs all day. I'm asking him to be a decent son by spending some time with his dad and thinking about his needs every once in a while instead of cavorting through his life like nothing has changed.
Also, this is not the first time I have had a conversation with my brother about these issues. Before my dad moved in with him I called my brother multiple times to tell him what to expect, the type of services our father would need, etc. He (my brother) has taken care of none of them. He can't even take 15 minutes to put our father on his car insurance (which my father would pay for) so that our dad could drive to the store when my brother gets home!
After a month or so of my father being with my brother, I got the sense of what was going on and called my brother to discuss it. I suggested that he find a senior center that does pickup and drop-offs. There is one close by, but it requires an initial sign up. That means my brother or his husband needs to take a few minutes one day during the week (which they can do) to take my dad to the senior center and help him fill out the forms, etc. After that he could be picked up at his home and taken to the center in the morning, and dropped off later in the day. Has my brother done that? No.
One thing that is illustrative of how my brother treats our father is the fact that in the 8 months my father was living with me, my brother called him exactly 4 times. And 3 of those times were in response to me facebooking my brother and telling him that he needs to call his father every now and then.
To his credit my brother does work a lot. He works a full time job during the week and takes gigs on the weekends for extra pay. He does not "need" the extra pay per se, but chooses to do that stuff so that he and his husband can go on an extravagant vacation every year. That was fine when he did not have the responsibility of taking care of someone else. But once he agreed to house and take care of our dad for part of the year, my view is that he needs to make changes to his schedule to accommodate that responsibility. Anyone who has had children understands the meaning of that kind of sacrifice. Its not fun, but it is what must be done. I would like to take an extravagant vacation too. But I don't because I have kids!
I get all the replies here that say that I should not expect my brother to be a caregiver. My response to that is, "isn't that what my brother signed up for when he agreed to take care of my dad for half the year?" It wasn't as though my father "had" to come back to the states. We wanted him to because instead of being taken care of by the Czech state healthcare system (with no one who cared about him within 3000 miles), we wanted him home so that someone who cared would at least be nearby.
As for whether my brother has any extra money to "donate to the cause," I will just politely chuckle and say that my my brother and his husband are some of the most financially irresponsible people I know. There is no chance in hell I could expect any money from him. Thankfully I do not need it.
As for my father's finances, he is on a very limited fixed income. ~$1500 a month between a combination of social security and a small alimony payment from my mother. Medicare parts A, B and D suck up ~$600 of that a month. So there is not much left over. Certainly not enough to live in a retirement community. He does have some meager savings. But again, not much.
To those saying that I am not going to change a 41 year old man, I say bullshit. For one, my brother is not a man. He is a child in a man's body. He has no clue what being a man is like because he has never ever had to act like one and never has acted like one. He has been coddled all his life because he was a rare musical talent, and everyone catered to him and forgave him for being a general dumbass when it comes to all things non-music. Now don't get me wrong. I do not hate my brother. I love him a lot. But I am the one person in his life that tells him what is what. And I don't sugarcoat stuff to spare his ego. I think he respects me for that, even though he might not like what I have to say all the time.