Common with international treaties. The trade agreement known as USMCA in the USA is known as CUSMA in Canada and T-MEC (Treaty between Mexico, USA, and Canada) in Mexico. Countries almost always put themselves first.
> Btw NATO and OTAN being anagrams is a coincidence
Not really, many initialisms are mirrors between French and English because their very similar languages in these contexts (same names and same etymology for nouns and adjectives means same letters) and grammatical rules are the opposite of each other (reversed letter order). Eg UN and NU, EU and UE, EEC and CEE, CCP and PCC…
Also related and because of the French: UTC. It was chosen as a concession between the logical English CUT or French TUC. Also the two are backwards, which I think is not really a coincidence due to word ordering rules in French.