The link below gives a good understanding of the why and how to the destruction and bloodshed going on in Yemen to which the MSM doesn't bother to give even the first syllable in the country's name.
Rumor has it (and as we know, rumors tend to become factual soon enough) that Saudi Arabia and its allies are transporting large batches of the undesirables from Syria and brand new ones from Nigeria, to Yemen. If true, expect many more refugees trekking their way away from Yemen and into the countries whose powers-that-be are deeply involved in each and every war ongoing on our planet.
....The economic and political gains
accrued by Saleh and his allies in North Yemen after unification meant that they could not let the south slip from their hands under any circumstances so unity was then imposed by force.
Unity by force is an occupation of South Yemen.
After the war of 1994 the south was seen as "spoils of war" and the elite of the north can do to the south as they please. So Saleh and his allies from the Islah party (Muslim Brotherhood, Alqaeda) began a campaign of assassinations of southern leaders, military officers, and activists. After the campaign of assassinations, thousand of military checkpoints were set up throughout the south and were ordered to kill and/or imprison secessionists.
Also, former president Ali Abdullah Saleh and his allies from the Islah party (Muslim Brotherhood) settled and financed Alqaeda (AQAP) in South Yemen in order to subdue southerners and keep South Yemen in shambles while northern security forces enforced the full occupation of South Yemen and Saleh and his allies looted southern land and resources. ....
....Mandatory retirement was forced upon 467,649 employees of the army, without giving them retirement benefits.
Confiscation of 42% of southern land specifically in Aden and the relocation of hundreds of thousands of northerners to the south in order to alter the demographic landscape of the south.
25 years of looting southern resources from oil and gas to agriculture and fisheries.
That's on top of constant killing of southerners and attacks on southern cities and villages by northern forces.....