- IRAN : not a treaty

- TTIP : did not sign the treaty, out of negotiation

- NAFTA : still in treaty, all three parties want changes and negotiating

- Paris accord : not a treaty

Having said that. US is the sole super power and it gets to make the rules. Given the domestic politics and economic realities the mid-west and specifically the steel belt, now the rust belt gets to decide the Presidency in the near-future. Populism is the new norm, no matter what the Coastal Elites feel or think!

The agreement with Iran and the Paris Accord were not submitted to Congress, and so did not have the weight of treaties. TTIP negotiations have been suspended and it has not been ratified. Like the president, Secretary Clinton publically opposed it during the presidential campaign. Trump has expressed an interest in renegotiating NAFTA but it's still in place.

The world does not care about the minutiae of US's internal political system. In the case of Paris, an agreement was signed and not respected.

Well, we don't care about your (deliberate?) ignorance. The difference matters to us.

In the case of Paris, the agreement was signed by someone who did not have the authority to bind the US to the agreement. If you felt that we are breaking our agreement, well, I can understand your disappointment, but the problem was your understanding of the situation, not the US's "not respecting agreements". (When someone "makes a commitment" for your country, who does not have that authority, do you want to be bound by it?)

Would you feel the same if it were President Trump who signed an accord, say, to subsidize greater greenhouse gas emmisions, and President Warren withdrew from it?

Most countries would not be signatories of such an accord, so there would be little to withdraw from.

Paris was a hard-fought compromise, involving concessions from all involved. A difficult negotiation, achieved with great effort and time investment, and shattered to pieces in two minutes.