Because these two terms are very common and so is the combination. For example, Israel -- the original prevailing ideology was nationalist (Zionism) and socialist (incidentally, this is the reason why Stalin supported creation of Israel).
Do you consider Israel to be an enemy to be destroyed too? If you do, I understand your position, if you don't , you are not being fair :P
You either grant every country the right to be nationalistic (helpful as long as this does not go too far) and experiments with socialism if they want to (usually harmful but not any of our business).
Your other error is in misunderstanding the term "socialism" as it is used in Baathism. Per Wikipedia:
Socialism in Ba'athist ideology does not mean state socialism or economic equality, but modernisation; Ba'athists believe that socialism is the only way to develop an Arab society which is truly free and united.
So, do not let yourself jump into false analogies with NSDAP, this is more about rejection of feodal past still present in many Arab countries (cf. Saudi Royals). I do not have a problem with this, and do not see why you should.
If by "democratic-republican rule" you are referring to our sorry domestic state, I certainly do not deny that fact. These are the enablers of foreign enemies, take note, while the identity of these foreign enemies does not change.
Oh, but it does change. Al Queda and ISIS are new enemies, obviously dangerous, and not merely enabled but created by our sorry rulers. But what makes Syria an enemy? Did I miss something?
OK; I see where you’re coming from now, calling Zionism “nationalist (and) socialist” especially when Israel is neither. This isn’t Stormfront, in case you didn’t notice.