Liberal interventionists share the desire to spread freedom and the conviction that outsiders can help do so, but they also care deeply about building international architecture (almost always) and respecting international rules (usually).
Liberals often differ sharply about, for example, humanitarian intervention: it's entirely coherent to self-describe as both a foreign policy liberal and believe that humanitarian intervention usually does more harm than good. Neoconservatism, by contrast, makes a belief in the morality and efficacy of preventative wars against rogue states (Iraq, Iran), nation-building endeavors (Afghanistan post-2009), and overwhelming US military dominance more broadly into bedrock principles. While liberals might endorse any or all of those three, it's not at all requried by liberal commitments that they do so.
I think they're both largely right and I don't have much to add. But I wanted to post this in relation to my previous post on the use of the term war in our political rhetoric. I encourage liberals to stop using that type of rhetoric for reasons relating to what is described above. We should be primarily committed to solving problems through diplomatic and economic means, which are often helped by using international institutions.
Much like I said conservatives do when they invoke the "war on ..." rhetoric, neoconservatives seem to go to the war option as their first response to a perceived problem. And in both instances they limit the policy responses of conservatives and then create conflict with liberals who want to be open to more policies. This intensifies the ideological divide and leads to further partisanship. That's why even though liberals and neoconservatives might have similar goals broadly, they can often disagree as to the proper policy in many international situations.