Two months before the NATO Summit in Bucharest in 2008, Russian Foreign Minister Lavrov warned US Ambassador William Burns pointedly of 'fears that the issue could potentially split Ukraine in two, leading to violence or even, some claim, civil war, which would force Russia to decide whether to intervene’.
Burns sent a cable to Secretary of State Condoleezza Rice which title was ‘Nyet means nyet: Russia’s NATO enlargement red lines’(Binney et al., 2014). Despite warnings on the future of Ukraine by President Putin who was present, the 2008 NATO Summit decided to invite Croatia and Albania to become members, and opened the door for eventual membership for Georgia and Ukraine.
The statement–pushed through by President Bush himself at the Summit–read:‘These countries will become members of NATO’(NATO, 2008). By doing so the West – and more in particular NATO–clearly transgressed Russia’s redline.
Russia reacted by provoking and invading parts of Georgia in 2008. The West in its turn did not react, which was noticed by Putin (Speck, 2014). One year later, Gazprom cut off all supplies to Ukraine, again without much reaction by the West. In hindsight, this episode can be regarded as aprelude to the Ukraine crisis.
Aviel Roshwald (2008), historyp rofessor at Georgetown University, predicted already in 2008, six years before the crisis:‘To let Ukraine join NATO would almost inevitably trigger a Moscow-orchestrated seces-sion from Ukraine of the ethnically Russian Crimean peninsula, home to the Russian navy’s Black Sea base’. It is remarkable that the foreign policy establishment in Washington DC and Brussels missed similar observations. Harvard professor Stephen Walt’s (2015) judgment is harsh: ‘The failure of US diplomats to anticipate Putin’s heavy-handed response [in Ukraine] was an act of remarkable diplomatic incompetence’. A similar remark can be made with respect to the Eurocrats in Brussels.

https://onlinelibrary.wiley.com/doi/...758-5899.12374