Countries that have been the victims of ISIS attacks should definitely retaliate and hold them accountable for their actions. However, the US hasn't suffered any attacks as of yet, and it would be unwise to reach out to start a conflict when it may not be necessary. There's no definitive proof that the US is in any danger from ISIS, but there could be danger if we provoke them.
The days of pursuing military objectives in a unilateral manner are a thing of the past. What the present fight against ISIS requires is a united military response from the major world powers in order to protect our way of life. Unless they work together, we risk committing the same mistakes of the past 15-20 years. The war effort itself, also requires a more active role for Middle Eastern actors who have demonstrated on some occasions to be part of the problem instead of the solution.
The United States should stop getting involved in wars and military actions in places that have nothing to do with the US. Those countries don't want us there, and taxpayers don't really want to fund the murder of other people. Please stop and use our tax dollars to support people in the US who need help.
No, the United States should not retaliate against ISIS. If the United States chooses to send troops to attack, ISIS may be more likely to initiate attacks on the USA. Currently, ISIS is concentrating on expanding their territory out of Syria and Iraq. If the United States chooses to attack, they may be more likely to bring their mission westward.