I was reading this article which includes the following estimates for the numbers of fighters involved in ISIS-related regions:
- Between 7,000 and 30,000 ISIS fighters. Mixed levels of training and motivation, mixed nationalities.
- Up to 190,000 peshmerga. Another article suggests this is an old estimate from 2012 of the total everywhere - but they've received much international support since then, so their current numbers may be higher, with an increasing focus on north Iraq. That article in August 2014 described them as "Increasingly well equipped... motivated, well trained and experienced"
- Around 250,000 in the official Iraq army. They may have performed exceptionally poorly so far, but the numbers advantage is huge.
Not all those peshmerga are involved in this conflict, but ISIS are also divided between many fronts, with other opponents such as the many Islamist splinter groups in Syria, the Syrian army, the FSA, international air forces, etc etc - plus all the difficulties in keeping the cities they have captured in a state of martial law and maintaining supply routes over a wide area.
And then there's also logistical issues getting supplies into the region. There may be plenty of rumours that they are receiving support from wealthy individuals in Saudi Arabia and elsewhere, but there's less of an obvious corridor for them to physically receive this assistance than there is for their opponents who are also receiving assistance from abroad.
So on paper, the numbers really don't look good for ISIS. However, they seem to have been gaining ground as fast as they are losing it, even after the addition of air strikes.
How? What's missing from this analysis that enables them to flourish when the numbers seem stacked against them? And what's stopping them simply being overrun by opponents who have greater numbers, easier access to fresh supplies and (for the Peshmerga) more unified forces with stronger motivation?