Just seems to me the easy solution would be to just let them fight it out among themselves but that just feels...cowardly and selfish.
It seems like embedded in your feeling that it is cowardly or selfish to 'let them fight it out among themselves' are some hidden assumptions:
1. The assumption that the US can force warring factions to stop fighting each other.
2. The assumption that the US really wants to force warring factions to stop fighting each other.
3. The assumption that the US's motives are really for peace and well-being of the people in those nations.
4. The assumption that the only meaningful way for the US to conduct foriegn relations in the mid east is by means of weapons and violence.
5. The assumption that the US knows what is best for other nations.
A survey of the past 30 years in Mid East history would cast doubt on some of those assumptions.
I'd love to see US foreign policy adopt the motto: 'First, do no harm.' I think if we did that, it might lead to fewer 'humanitarian bombing missions.'
It amazes me that Americans seem unwilling to see the connection between the attack on the US embassy in Libya and the fact that in 2011 the USA intervened in their revolution and bombed the country.
The British had a notion of 'White Man's Burden,' which was used to justify their imperialism for the last 60 or so years of the British Empire. The USA has a similar conceit that it uses to conceal it's imperialism.