France's Maginot Line, a vast World War I-era fortification, was rendered useless in World War II as Germany simply bypassed it with blitzkrieg tactics. This historical example illustrates how preparing for the last war can lead to failure in the next. The author argues that corporations are making a similar mistake in AI governance by favoring experienced, often retired, executives for board positions. While experience is valuable for tackling familiar challenges, it often lacks insight into emerging threats like AI. Most S&P 500 companies recognize AI as a risk, yet few of their directors possess AI expertise. Boards risk building a "Maginot Line" by relying on past experience instead of actively addressing current AI-driven disruptions. To counter this, boards should prioritize directors with current operating experience in relevant technologies. They also need to establish channels, like shadow boards, to gain insights from employees directly using AI. Finally, directors should have a personal stake in the long-term consequences of AI decisions. Boards should rebalance, not replace, experienced members by adding fresh perspectives and not solely delegating AI oversight. Failing to adapt will leave companies vulnerable to unseen threats, mirroring France's historical miscalculation.