Quote Originally Posted by Philipvs Vallindervs Calicvla
Wiki is wrong. After Marius the legions were often kept under arms because of the almost constant state of war, the term of service was actually fixed under Tiberius according to Tacitus.
But with a near-constant state of war, wouldn't that just mean that the state of readiness of the Roman legions was kept high just as much as it would have been in a peacetime professional army? Perhaps even more, actually.
So in that light, the Roman forces should perhaps be treated as a professional standing army even if they were not formally a standing army.