Star Trek: Discovery (2017) S4 E10
Euringer 3 points 2 years ago*. (Contains Spoilers)

Sorry, wasn’t trying to make a semantic point or be rude, feel free to ignore my explanation but: The Romulan treaty is presumably null at this point because of the “unification” in the 3,000’s. I think it may have already been kind of a suggestion by the time of Picard though because in Deep Space 9 the Romulans loan the Defiance a cloaking device under the agreement that they won’t use it in the Alpha Quadrant, but the Federation not only uses it they clone it for the minefield during the Dominion War.

Xsile 3 points 2 years ago*.

There was also the Pegasus from the next generation, that had a top secret federation cloaking device. Though that device was clearly against the treaty of algeron.