Why fully European military systems would take decades

Will Europe eventually develop fully European military systems, and how long would that take?

Possibly over decades, but rebuilding the technology base would be costly and current American systems cannot simply be removed before replacements exist.

Fully European military systems would require Europe to build more of its own technology base and fund a long development effort. The expectation is that such independence could take decades, with political integration raised as a possible condition for financing it. Greater autonomy is welcomed, but abruptly excluding all American components would create equipment gaps. Systems such as the Mark 41 vertical launch system cannot be rapidly replaced with newly developed European equivalents. Interdependence therefore constrains how quickly procurement can change.