You should say from liberal interventionist to neocon is not that big a step.
You may recall that Joe Lieberman was a very hawkish liberal interventionist and was some times called a "leftwing neocon". That's why Lieberman was good buddies with NeoCon John McCain. And why John McCain truly loves Hillary.
“You should say from liberal interventionist to neocon is not that big a step.”
That’s a good point. Neoconservatism originated with liberals and even Trotskyite leftists who were foreign policy hawks. They advocated the Liberal Internationalism that guided American foreign policy from WWII right on through the end of Vietnam.
Neoconservatism was a reaction against ‘Blame America First’ liberals who believe that America is the destabilizing, if not evil, force in world politics. (If that sounds like Obama there’s a good reason for it)
With the Blame America First crowd seizing power in the Democratic Party during the 1970s the nascent Neocons found Ronald Reagan’s no nonsense foreign policy more to their liking. So they joined forces with Reagan conservatives in groups like The Committee on the Present Danger to promote a strong foreign policy. In fact they often favored a more interventionist foreign policy than Reagan.
The problem for conservatives is that Neocons still hold on to many leftist social policies and they try to promote them. They work against border control and for illegal alien amnesty. Neocons are usually just fine with gun control laws. They don’t oppose and they often promote the gay agenda. On anything touching race they will be predictably on the left even though ‘civil rights’ regulations have been a major force for increasing government intrusion in everyday life.
They aren’t lockstep on this of course, but on most domestic and social issues Neocons are far more in line with liberal Democrats than they are with conservatives. It’s on economic and especially foreign policy issues that they will join with conservatives.