Precursor to War?

 It has transpired that many of the world's large powers are increasing their defense spending the US, China, India, Russia, Japan, South Korea, and certain countries in Europe. This may very well be a common trend, however, it does not disprove the trajectory the world faces. It is well established that US global hegemony is deteriorating from both internal and external factors. Such a decline, albeit slow, may be measured in how other countries increase their own dependence on on self-defense. Defense budgets are an obvious metric to observe (but cannot provide the fullest narrative) this self-dependence. The allies of the US may be putting more trust in their own capabilities. Furthermore, both China and Russia along with any other minor parties are actively seeking a more multipolar world. 

With multiple factors at play, are increased defense budgets an effective way to "predict" war? Do increased budgets indicate a more multipolar world? And if other countries do continue reliance on decaying US power, will they become vulnerable in the future when the US can no longer help them and have to retreat into itself?