William Muir,
The Caliphate: Its Rise, Decline and Fall…
“ From a Court weakened thus by continual change and treachery, there was little, one might think, to fear, but Al-Muthanna had to guard a frontier of great extent, and for the task his army was inadequate. The inhabitants were, at the best, indifferent; the Syrian Bedawin distinctly hostile. Victories might be won but could not be followed up. The position, with so small a force, was full of risk. Accordingly, Al-Muthanna urged upon the Caliph the pressing need of reinforcements. ”
