Why do European nations need to increase defense spending according to NATO?

According to the clip, European nations must increase defense spending because Russia poses a threat not only to Ukraine but to all nations. The expert emphasizes that the most important takeaway from their meeting is the collective need to 'step up' regarding defense expenditures. This urgency stems from recognizing Russia as a broader security threat that extends beyond the Ukraine conflict. The expert explicitly states that all nations need to both 'scale up' their defense capabilities and 'speed up' this process, highlighting the immediate nature of the security challenge facing European countries and NATO allies.