An important basic condition for being appointed to this position is unanimity.
Clearly, the conflict between the Russian Federation and Ukraine plays the most important role. Romania has the longest border with Ukraine, deterrence is very important here. It is of course widely known that the Netherlands has not yet met its 2% minimum obligation 
and Romania is well above this standard. Klaus Johannis is seen within the EU and NATO as a reliable ally and best known for his strategic insight. Romania is a politically stable country and unfortunately we cannot say the same of the Netherlands. In NATO circles, his decisiveness is well known when he took the initiative in 2015 to form a first buffer with 9 Eastern European countries against the aggressiveness of the Russian Federation. The war in Ukraine began not in February 2022, but as early as 2014 with Russia’s illegal annexation of Crimea and the secession of the self-proclaimed People’s Republics of Donetsk and Lugansk.
This initiative has the name of B9, i.e. the B of Bucharest and the number of countries participating in it.
