NATO has previously promised not to expand eastwards and NATO has broken international agreements.
Recurring pro-Kremlin disinformation narratives on NATO. As explained by the DFRLab, both statements have been debunked numerous times. NATO made no promises not to expand into eastern and central Europe back in 1990, which was confirmed by the former president of the Soviet Union Mihail Gorbachev. Back in 2014, Gorbachev said:"The topic of ‘NATO expansion’ was not discussed at all, and it wasn’t brought up in those years. I say this with full responsibility." https://www.rbth.com/international/2014/10/16/mikhail_gorbachev_i_am_against_all_walls_40673.html. Furthermore, the claim about NATO "expansion" misrepresents the process of NATO enlargement. NATO does not "expand" but considers the applications of candidate countries which want to join. In any case, no such promise was made https://www.nato.int/cps/en/natolive/topics_109141.htm.
Similarly, NATO did not break the “Substantial Combat Forces” pledge of the 1997 NATO-Russia Founding Act. The pledge precluded “permanent stationing of substantial combat forces” in the region. http://www.europarl.europa.eu/RegData/etudes/ATAG/2016/583782/EPRS_ATA%282016%29583782_EN.pdf. The four multi-national battle groups deployed in Poland, Lithuania, Latvia and Estonia are rotational, defensive, and well below any reasonable definition of “substantial combat forces.” Further debunking at DFRLab https://medium.com/dfrlab/balticbrief-russia-claims-secret-nato-deployment-e6c0e649ccfb.