Q&A about Arab peacekeeping force.

• Position: News

CAIRO -- Arab League member states have agreed in principle to form a joint inter-Arab military peacekeeping force. While details of how such a force would actually operate remain thin, the agreement is a telling sign of a new determination among Saudi Arabia, Egypt and their allies to intervene aggressively in regional hotspots, whether against Islamic militants or spreading Iranian power. Here's a look at some of the questions surrounding the plan:

How will the joint force work?

Senior officials from participating counties have been dispatched to collectively examine the issue and report back within about a month. Egyptian President Abdel Fattah el-Sissi, a strong proponent of the idea, has described the force as an absolute necessity. Egyptian military and security officials have said the proposed force would be made of up to 40,000 elite troops and will be headquartered in either Cairo or Riyadh, the Saudi capital. The force would be backed by jet-fighters, warships and light armor.

Who will lead it?

Saudi Arabia, as the region's economic powerhouse, will likely take a leadership role. Egypt, which boasts the Arab world's largest standing army, will also be a major player. However Egypt is heavily dependent on financial aid from Saudi Arabia and other Sunni Gulf Arab nations who have donated billions to bankroll the country's struggling economy. The combination of common concerns between Riyadh and Cairo and economic dependence will probably mean that the specific concerns and fears of the Gulf Arab monarchies will hold sway.

Is there any precedent for this?

Creation of such a force has been a longtime goal that has eluded Arab nations in the 65 years since they signed a rarely used joint defense pact. Gulf...