Though the White House may be able to largely run domestic issues, at the least, I do think other forces are at play in some of these foreign policy decisions, shadow government or it almost seemed with the Obama administration and Clinton Secretary of State, maybe they did favors for other countries based on donations.
If there is a shadow government, yes, they can make a mess of things as well.
I think Iraq/Syria was botched up so much by the Obama administration that the Pentagon brass, maybe other agencies, took over how these wars were run.