On to issues in 2 & 3, in response to Kysar's The Global Tax Deal and the New International Economic Order.
2. How can we explain emerging multilateralism in international tax policy, given the barriers to successful cooperation? In the prior blog post, I was discussing the factors affecting support for tax multilateralism in a single country, focusing primarily on the US. However, even if countries want to act cooperatively, this may be hard to pull off.
At least two considerations may tend to make it a tough uphill climb. First, countries often have very distinctive or even conflicting interests. For example, one has both developed and developing countries. Net capital importers versus exporters. The US versus the EU with respect to the latter's taxing the big US multinationals. Second, there can often be zero-sum conflicts. For example, do we get a given dollar of tax revenue, or do you?
The paper mentions the common interests that countries also have (e.g., from the tax competition prisoner's dilemma perspective). While I agree that this is part of the story, I'd also add a second factor.
A standard story about irreconcilable differences (especially if not steeped in contemporary IR theory) might rest on two background assumptions that are not always true. The first is that each country has a clear national interest. The second is that a country's political actors proceed in good faith to advance this interest, as faithful agents for the country as a whole.
This is not always a bad framework to use. For example, it can help one to understand Ireland's decision, in the early stages of the Pillar 2 process, that its best play (all things considered) was to go along and secure a place inside, rather than outside, the tent. Or consider Poland's and Hungary's making financial demands of the EU before they would withdraw their objections to Pillar 2.
But for a more complicated story, consider US domestic politics. The Biden Administration and Congressional Republicans fundamentally disagree about where the national interest in international tax policy lies. (And this is not a Trumpist phenomenon - the divide has been around for decades, and a version of it can also be seen in the academic literature.)
Without getting into all the details here, as will be explored in a paper that I am currently co-authoring with Daniel Hemel (the title will be something like Two-Level Games in International Tax), domestic players routinely use the foreign realm as an arena through which they can respectively try to advance their own sides' prospects in domestic political fights. [We'll have an OECD-BEPS case study in our paper, but also one from 1957, involving Stanley Surrey and the battle over the "tax sparing" provision in a draft treaty with Pakistan. We might also have had a 1920s League of Nations case study, involving the likes of ERA Seligman and TS Adams, but we concluded that we weren't sufficiently sure-footed in the literature to be certain that the story we thought we saw was actually right.]
International tax cooperation is made easier in one dimension by these two-level games, which can foster cooperation and common interests between the players on each side (in re. how to tax business) in multiple countries.
3. A new international economic order? In using those words, at least in the current draft, the paper might seem to be claiming more than it actually is. Things are still clearly in flux, although Pillar 2 (but not Pillar 1) appears to be doing fairly well even if US cooperation is, at best, not in the immediate offing. But the claim is that, with the decline of the neoliberal "Washington Consensus," concerns about distribution between and even within countries are now very much on the agenda internationally. And there is also some hope that they may come to be negotiated out to a degree, using compromise to build broad agreements.
A different way to put it might be to say that the international tax policy agenda has changed, and that topics once deemed off-limits are now widely (if not universally) agreed to be on the table. If pro-democracy forces prevail around the world - as is by no means certain - one might even see, at some point, a new and improved such order gradually emerging, at least until the next set of shocks leaves us unmoored again.