This is the 14590th most frequent Russian word.
первопричиной
"Первопричиной" means "the primary cause" or "the root cause."
The word 'первопричиной' is used here in an instrumental case form as part of a predicate to indicate that the lack of resources is assigned as the primary or root cause of the delay.
Организация определила отсутствия ресурсов как первопричиной задержки проекта.
The organization identified the lack of resources as the root cause of the project's delay.
In this sentence, 'первопричину' is in the accusative case as it serves as the direct object of the verb 'понять' (to understand), indicating what is being understood.
Наука стремится понять первопричину природных явлений.
Science strives to understand the root cause of natural phenomena.
Here, 'первопричиной' is used as a predicate nominative in the instrumental case following the verb 'являются' to attribute the primary cause to economic issues.