Ireland is part of the EU, so how it taxes corporations is something it has to negotiate with the rest of the EU. That is its problem, not something the G7 care about. Ireland has attracted investment and revenue by undercutting other nations, while providing access to the EU. Not surprisingly, the rest of the EU is not happy about that.
No one is denying nations the right to set their own tax rates for corporations. What has happened here is that a number of nations have come together, negotiated, and agreed that they will each set their lowest rate at 15%.
The reason for that is deliberately to stop countries undercutting each other. They have all agreed that undercutting each other has lead to consequences that have affected them all equally in a "race to the bottom" and of corporate tax avoidance.
> If they are economically harmed by someone else having a 10% rate...
The G7 nations have agreed that they don't want to be economically harmed. Their agreement is to pass laws in each of their environments to stop that. They've also agreed that each of them can tax the profits made locally to them. They agreed to limit that to a maximum of 20% of the corporate's global profits.
As for the 2/3rds rule for US treaties, that's because the Senate, representing the States (not the people), is given a "check" over the President unilaterally making treaties, as far as the United States is concerned, because treaties made in this way are considered equal in power to the Constitution. Each treaty is effectively an amendment to the US Constitution.
So it's not about 51 vs 49%, it's about 2/3rds of the US states, as represented in the Senate, agreeing with a treaty.
Evidently you know little or nothing about the EU. Taxation by member states of the EU is a sovereign national competence and the Irish have both a veto over change and a likely requirement to hold a national referendum over any change.
If you do some research you'll find that there is zero evidence of any EU countries shifting profits to Ireland. Almost all of the profit shifting which Ireland is blamed for facilitating is undertaken by a handful of US MNCs enriching their shareholders at the expense of US taxpayers via mechanisms enabled first and foremost by the US govt
No one is denying nations the right to set their own tax rates for corporations. What has happened here is that a number of nations have come together, negotiated, and agreed that they will each set their lowest rate at 15%.
The reason for that is deliberately to stop countries undercutting each other. They have all agreed that undercutting each other has lead to consequences that have affected them all equally in a "race to the bottom" and of corporate tax avoidance.
> If they are economically harmed by someone else having a 10% rate...
The G7 nations have agreed that they don't want to be economically harmed. Their agreement is to pass laws in each of their environments to stop that. They've also agreed that each of them can tax the profits made locally to them. They agreed to limit that to a maximum of 20% of the corporate's global profits.
As for the 2/3rds rule for US treaties, that's because the Senate, representing the States (not the people), is given a "check" over the President unilaterally making treaties, as far as the United States is concerned, because treaties made in this way are considered equal in power to the Constitution. Each treaty is effectively an amendment to the US Constitution.
So it's not about 51 vs 49%, it's about 2/3rds of the US states, as represented in the Senate, agreeing with a treaty.