What happened in Paris is not right, just inevitable
Since 2011, France has been militarily involved in five countries -- four of which have a predominantly Muslim population:
Syria (2015, 87% Muslim)
Iraq (2014, 99% Muslim)
Mali (2014, 90% Muslim)
Central African Republic (2013, 15% Muslim)
Libya (2011, 97% Muslim)
France struck the first blow by dropping bombs in Libya, Mali, Iraq and Syria. The Islamic State didn't start this fight.
Again, it doesn't make what the Islamic State did right, but when one country drops bombs in another country they make it more likely that someone is going to attack them in their own country.
"Let France and all nations following its path know ... that the scent of death will not leave their nostrils as long as they partake in the crusader campaign ... and as long as they boast about their war against Islam in France and their strikes against Muslims in the lands of the Caliphate with their jets," read their statement.
There are those who say the Islamic State is going after all western countries because of the west's way of life. If that were true then why haven't they targeted countries like Switzerland and Brazil?
And if the Islamic State is public enemy #1, why are France and the US opposed to those who are actually fighting the Islamic State? Syrian president Bashar al-Assad, the Houthis in Yemen, Russia and Iran are all fighting the Islamic State, yet each one of those is and 'enemy' of the US. When it comes to these groups and the targeted governments, the US is on the same side as the Islamic State.
France had it right when they refused to support the US-led invasion of Iraq in 2003. Had the US never invaded Iraq, the Islamic State would not exist and the attacks in Paris may not have occurred.
One hopes France recognizes that the way to prevent acts of terror in their country is by not committing acts of terror (which is what war is) in other countries.