Why have Rwanda-backed rebels seized 2 Congolese cities and is there an end in sight?

Rwanda-backed rebels have captured two key cities in Congo’s mineral-rich east in less than a month after a major escalation in their yearslong fighting against overstretched and weakened Congolese forces.

With the support of thousands of troops from neighbouring Rwanda, the M23 rebels first took Goma last month before marching to Bukavu this weekend in an unprecedented advance since they took up arms more than a decade ago, further…