NS2 should not have existed in the first place. Don't you feel shame for building huge pipeline around whole Eastern Europe just so your trade wouldn't be interrupted as russia invades everything? Because you should feel the shame. It have been built when russia already invaded Ukraine.
And yes, it wasn't yet used, but almost finished state of it gave russia more courage to launch full scale invasion.

You do understand that late 00s is when pro-Ukrainian president in Ukraine have been elected, and russia was using economic pressure as an instrument to make him unpopular and, as a result, installed pro-russian puppet Yanukovich?
And instantly all the gas issues vanished, 30% discount was given, in exchange for permission to extend Russia's lease of a major naval base in the Ukrainian Black Sea port of Sevastopol for an additional 25 years - the soldiers from this base occupied Crimea in 2014.