As a person fluent in both Arabic and English, I always wonder if Arabic dialects count as "languages". Note that basically no one speaks "written" Arabic; everyone uses a dialect based on their region.
For example, North African dialects are basically unintelligible to Middle Easterners. Even within North Africa, the dialects are vastly different: for instance, Tunisians have trouble understanding the general Algerian dialect. You can go even further: people within Tunisia can find trouble understanding each other's dialects (e.g., north vs. south)! The linguistic variations are enormous.
I was raised in the UAE, so I can understand (at a high level) basically all Arabic dialects. In Tunisia, I speak Tunisian; in the UAE, I speak the dialect closest to who I'm talking to (if applicable), or a form of Emirati Arabic otherwise (e.g., in the case of Sudanese Arabic).
Whether something is a language or a dialect is a political question, not a linguistic one. The Arabic dialects are as varied as the Romance languages in grammar and vocabulary.
While this is true to some extent, I think the question is mostly one of mutual intelligibility; that is, whether a speaker of dialect A and dialect B can understand each other by each speaking their own dialect. This is obviously a spectrum - there can be no mutual intelligibility at all, some amount of mutual intelligibility (like among some of the romance languages), near full mutual intelligibility, and full mutual intelligibility. So, where the line is drawn depends upon political factors.
Despite all of the PRC's claims to the contrary, Chinese is not a single language but a language family. There isn't really much you can do politically when mutual intelligibility is low.
For example, North African dialects are basically unintelligible to Middle Easterners. Even within North Africa, the dialects are vastly different: for instance, Tunisians have trouble understanding the general Algerian dialect. You can go even further: people within Tunisia can find trouble understanding each other's dialects (e.g., north vs. south)! The linguistic variations are enormous.
I was raised in the UAE, so I can understand (at a high level) basically all Arabic dialects. In Tunisia, I speak Tunisian; in the UAE, I speak the dialect closest to who I'm talking to (if applicable), or a form of Emirati Arabic otherwise (e.g., in the case of Sudanese Arabic).