<ul data-eligibleForWebStory="true">Onebrief, a defense tech startup, raised $20 million in funding, pushing its valuation over $1 billion.The startup's AI platform aids military planners in building and coordinating complex operational plans efficiently.Onebrief has experienced significant growth, with roughly 19,600% annualized growth in operational usage.The company's software streamlines military planning tasks traditionally compiled in lengthy documents.The latest funding round was a $20 million Series C extension led by Battery Ventures.Onebrief's total funding now exceeds $120 million, with a valuation increase of over $400 million this year.The surge in venture investment in defense tech has propelled sectors like Onebrief.VC investments in defense-related companies grew 33% year-over-year, reaching $31 billion in 2024.Funding rounds in 2025's first quarter totaled $1.4 billion.Onebrief's CEO Grant Demaree, a West Point graduate, highlights the importance of swift military planning.Battery Ventures was drawn to Onebrief due to the platform's potential in future geopolitical conflicts.The ability to plan more effectively and quickly is seen as key to enhancing global security.The company's platform, powered by AI, plays a crucial role in military planning.Demaree's military experience influenced the development of Onebrief's planning solutions.To view the pitch deck used by Onebrief to secure funding, check out the original article on Business Insider.