Infograph: Rich against poor

The Saudi-led bombing campaign in Yemen has pitted the air force of one of the richest Arab countries against rebel forces in one of the poorest.

Years of conflict and lack of development have left millions of Yemenis in poverty. In 2012, the UN warned that 44 percent of the population - over 10 million people - were food insecure. International humanitarian agencies were predicting a humanitarian crisis well before the current round of fighting began.

Experts have warned that Sanaa could easily become the first capital city in the world to run out of a viable water supply.

By contrast, Yemen’s northern neighbours enjoy some of the highest standards of living in the Arab world. Saudi Arabia, the world’s biggest oil producing nation, and the other members of the Gulf Cooperation Council (GCC) all have high per capita incomes, near universal access to clean water, electricity, education and health.

They may share a thousand-mile-long border, but economically speaking, Yemen and Saudi Arabia are two different worlds.

Rich against poor. We check the numbers [Graphic Claudia Mateus]