How did Frederick William try to keep Brandenburg out of conflicts between Sweden and the Habsburgs?

To escape the pressure of rival powers during the early years of his reign, Frederick William initially pursued a policy of cautious neutrality. Upon succeeding his father in 1640, he sought to distance Brandenburg from the ongoing conflicts by discharging Brandenburg troops that had been serving the Habsburgs and concluding an armistice with Sweden.1

Recognizing that neutrality required strength, he began organizing his own military force in 1644 to ensure he could master his own house. Throughout his reign, he avoided simple neutrality in favor of a strategic balance of power policy, which involved shifting alliances to support the weaker power against the stronger to advance the interests of his house. This approach, often referred to as Brandenburg's intermittent fever, allowed him to navigate the complex geopolitical landscape between Sweden and the Habsburgs, though he frequently had to adapt his stance based on changing military realities and external pressures.12