We introduce StrategicAI, a decision support system (DSS) for organization leaders and managers responsible for making strategic decisions on the course of their organizations. The main idea behind StrategicAI is to reduce the inherent complexity of strategic decisions using logic trees. These tree structures recursively decompose the involved problem and solution spaces into less-complex parts until these parts become straightforward to answer based on known information. StrategicAI follows a human-AI collaboration philosophy where users are in full control of the tree decompositions applied and can decide flexibly which parts of the trees they create manually and which parts the artificial intelligence (AI) creates. The AI is a multi-agent system based on retrieval-augmented large language models (LLMs). To obtain data-driven insights, StrategicAI actively retrieves facts from user-uploaded files and online sources and incorporates them throughout the created trees. A demo video is available at https://youtu.be/uKx8L4XZI9A . We release our code at https://github.com/PortgasXDXMajd/StrategicAI .