Why is the US now going to bail out Greece?
For the same reason we keep bailing everyone and everything else out. In the short term, not bailing out Greece could lead to a domino effect of sovereign debt default in numerous countries and global depression. Then all of the government leaders would get voted out of office and lose power. A few more hundred billion dollars may keep the ship floating long enough for all of the government leaders to make it through the next election cycle. They prefer to let a future generation of government leaders worry about the long-term problem of paying off the debt.