What happened
Nord Stream 2 was approved and built after Russia had already demonstrated, via the 2014 annexation of Crimea, a willingness to use military force to redraw European borders. Eastern European allies — Poland and the Baltic states in particular, who had direct historical experience of Russian domination — warned consistently that the pipeline would make Germany, and by extension the EU's collective bargaining position, hostage to Russian gas supply decisions.
Merkel's government proceeded regardless, framing the pipeline as a purely commercial infrastructure project separable from geopolitics — a framing most European security analysts rejected at the time and that collapsed entirely after February 2022, when Germany found itself needing to rapidly replace roughly half its gas supply, faced a domestic energy price shock, and had to reverse a decade of policy in a matter of months.