This is an odd claim:
According to balance-of-power logic and by its “balance of threat” alternative, the region should have witnessed a Turkish-Saudi-Israeli alignment aimed at Iran. Pooling resources makes sense since no single state can match Iran’s power. Israel and Saudi Arabia both seem to identify Iran as their major threat, and although Turkey may not be as focused on Iran, it still worries about Iran’s growing regional reach. A Turkish-Saudi understanding makes perfect sense by the sectarian logic that many believe is driving regional politics, as both are Sunni states. But neither the trilateral nor the bilateral balancing alignment against Iran has emerged.
2015 Defense Budgets (estimated):
Saudi Arabia: $80.8 billion
Israel: $23.2 billion
Turkey: $22.6 billion
Iran: $10.2 billion
The author, Greg Gause, goes on to argue that a variety of ideological factors are leading to “underbalancing,” and thus preventing the expected anti-Iran alliance to form. I’d suggest that before we conclude that “underbalancing” is happening, we need to have some explanation for why the massive military superiority that each of the potential coalition partners enjoys over Iran isn’t actually massive military superiority. Gause doesn’t offer one; I’m guessing that maybe he thinks the Saudis don’t actually fight and thus don’t really count, but nobody seems to believe that about the Israelis or the Turks. Indeed, I’m not sure I’ve ever seen anyone plausibly argue that Iran enjoyed a military advantage over either Israel or Turkey. And lest we forget, Israel, Turkey, and Saudi Arabia are all clients of the world’s largest military power, while Iran has no serious patron.
Thus, I’m inclined to think that there’s no puzzle here. The major Middle Eastern states have not formalized alliance arrangements to balance against Iran because they don’t need to; each enjoys presumptive military superiority over the potential aggressor, making multilateral efforts pointless. See also this discussion of Iran’s foreign policy failures.