“…it is what is observed and it accords with reality.”
I say: This is an astonishing and singular claim. Even granting that it is indeed observable and in line with empirical reality, that does not automatically make it in accord with the Sacred Law—first of all. Second, the very notion of “regions” or “horizons” is relative; they have no physical boundaries that people can clearly discern and stop at.
By Allah, I do not know what led the author to adopt this atypical opinion and to turn away from the unrestricted wording of the sound hadith—especially when it is the position of the majority, as he himself acknowledged, and when many rigorous scholars have endorsed it, such as Shaykh al-Islam Ibn Taymiyyah in al-Fatāwā, vol. 25, al-Shawkānī in Nayl al-Awtār, and Ṣiddīq Ḥasan Khān in al-Rawḍah al-Nadiyyah 1/224–225, among others. It is the truth; no other view is sound, and the hadith of Ibn ʿAbbās does not conflict with it for reasons set out by al-Shawkānī (may Allah have mercy on him).
The stronger explanation is perhaps this: the hadith of Ibn ʿAbbās concerns someone who began the fast on the basis of his own country’s sighting and then, midway through Ramadan, learns that people in another land sighted the crescent a day earlier. In such a case he continues fasting with his own community until they complete thirty days or sight their own crescent. Thus the difficulty is resolved, and the hadith of Abū Hurayrah and others remains general: it applies to everyone who learns of the crescent’s sighting from any land or region, with absolutely no distance restriction, just as Ibn Taymiyyah stated in al-Fatāwā 25/157. Nowadays this is extremely easy to achieve, as is well known, though it does require some concerted effort on the part of Muslim states to turn it into a practical reality, if Allah wills.
Until the Muslim nations unite on this matter, I hold that the citizens of each country should fast with their own state and not divide among themselves—some following their state, others following a country that began earlier or later—because that only widens the circle of disagreement within a single populace, as occurred in certain Arab countries a few years ago. And Allah