

What qualifications would that be, that helped in the job as president im what way exactly? A master in not-being-an-asshole? Or a bachelor in Listening-to-experts-while-deciding-in-favor-of-all-humans? Surely the US could use a requirement of a PhD in Anti-Corruption.
That snarky list aside, what makes leaders great/very good is not learned in higher education. Yes, in some situations having a bit of knowlege can help, but it is far from the most important (additionally even with a PhD you would only be expert in one field). It is not missing education, that made people like Trump, Putin, Xi or any other of the world leaders that bad. You can even be very intelligent, smart and highly educated and still be an asshole ready to through everyone in the wood chipper to gain more money and power.
Add to that, that higher education is already more available to rich, white people (especially in the US) and you essentially excluded most people from minorities with that rule. The capitalist world is already bad enough in that regard without some education requirements.
In the real world you could look at Nauru, which was a very low tax money laundering haven in the specified time frame. Though its a very small country with an interesting history.
The reaction of other states probably depends on how big of a problem that state is in the grand scheme of things. When the money laundering is too severe at some point international alliaces will impose sanctions, cutting of money tracks. For that to not destroy the countries economy, they would need powerful external friends. Probably some kind of world powers, that hold a protecting hand over them for geopolictical strategy.
Also: In such a place there would be people from all over the world, even the big world powers, doing shady bussiness. For the secret agencies of big countries such a money laundering haven can be a good opportunity to pipe money to some cronies. Think of the CIA financing groups of terrorists/militias to disturb a too socialist country, or even bringing its government to fall and be replaced by one doing the US favors (Osama bin Laden comes to mind).