https://sipri.org/media/press-release/2018/global-military-spending-remains-high-17-trillion
https://www.eca.europa.eu/Lists/ECADocuments/SR21_08/SR_Frontex_EN.pdf
https://ec.europa.eu/info/sites/default/files/joint_communication_-_defence_investment_gaps_analysis_and_way_forward_0.pdf
https://www.friendsofeurope.org/insights/critical-thinking-navigating-the-new-world-order-reflection-on-the-nato-summit-in-washington/