There actually seems to have been a promise made, back in 1991, that NATO wouldn't expand eastward beyond Germany. Somebody did some research deep and found an

There actually seems to have been a promise made, back in 1991, that NATO wouldn't expand eastward beyond Germany. Somebody did some research deep and found an assurance like that in protocols, Spiegel reports https://www.spiegel.de/international/world/nato-s-eastward-expansion-is-vladimir-putin-right-a-bf318d2c-7aeb-4b59-8d5f-1d8c94e1964d https://www.spiegel.de/international/world/nato-s-eastward-e... Or if you want just the quote out of the protocol by the researcher, see here: https://twitter.com/shifrinson/status/1160540400760832000/photo/1 https://twitter.com/shifrinson/status/1160540400760832000/ph... Not sure how binding such an assurance is or should be.