Transatlantic solidarity in the shadow of the Russian–Ukrainian war: a neorealist explanation

The threat posed by Russia, which was exposed most clearly following the invasion of Ukraine in February 2022, provided the impetus to strengthen solidarity among the transatlantic allies. Notable consequences included a renewed sense of purpose for NATO and the strengthening of the EU's resolve in responding to a crisis in its backyard and a willingness by many European states to do more to contribute to defence. Whilst there is apparent unity of intent in supporting Ukraine in the long term, this article argues that solidarity rests upon a familiar working pattern in transatlantic relations. This can be elucidated most clearly by a neorealist perspective. Balance of power considerations is important to maintain solidarity across the Atlantic. I illustrate this argument by showing how there was an increase in transatlantic solidarity from when Putin amassed troops at the border with Ukraine in November 2021 to the moment after the invasion of Ukraine in February 2022. The conclusion discusses the implications of the argument.