There are many moving parts to the grain deal Russia and Ukraine reached, which officials didn’t think was even possible until last week, not least because the war is continuing and trust between the parties is extremely low.

Here’s what to know about the grain problem, and how it might now be addressed.

After Russia invaded Ukraine on Feb. 24, it deployed warships along Ukraine’s Black Sea coast. Ukraine mined those waters to deter a Russian naval attack. That meant that the ports used to export Ukrainian grain were blocked for commercial shipping. Russia also pilfered grain stocks, mined grain fields so that they couldn’t be harvested and destroyed grain storage facilities.

A joint command center with officials from Ukraine, Russia, Turkey and the United Nations will be set up immediately in Istanbul to monitor every movement of the flotillas.

The ships will head into Turkish waters, to be inspected by a joint team of Turkish, U.N., Ukrainian and Russian officials, then deliver their cargo to destinations around the world, returning for another inspection by the joint team before heading back to Ukraine.

The agreement specifies the inspection team’s primary responsibility is to check for “unauthorized cargoes and personnel on board vessels inbound to or outbound from the Ukrainian ports.” A key Russian demand was that the returning ships are not carrying weapons to Ukraine.

The parties have agreed that the vessels and the port facilities used for their operations will be safeguarded from hostilities.

The operation is expected to quickly begin shipping five million tons of grains out per month. At that rate, and considering that 2.5 million tons are already being transported by land and river to Ukraine’s friendly neighbors, the stockpiles of nearly 20 million tons should be cleared within three to four months. This will free space in storage facilities for the new harvest already underway in Ukraine.

No broad cease-fire has been negotiated, so the ships will be traveling through a war zone. Attacks near the ships or at the ports they use could unravel the agreement. Another risk would be a breach of trust or disagreement between inspectors and joint-command officials.

The role of the United Nations and Turkey is to mediate such disagreements on the spot, and to monitor and enforce the agreement. The agreement is valid for 120 days, and the U.N. hopes that it will be renewed.

No. Global hunger is a constant problem caused by poor distribution of food andprice manipulation, hitting some parts of the world year after year. It is often compounded by conflict and has also been affected by climate change. The war in Ukraine, which produces a large share of the world’s wheat, added an enormous burden on grain distribution networks, driving up prices and fanning hunger.

Officials say the agreement has the potential to increase the flow of wheat to Somalia within weeks, averting a full-blown famine, and should lead to a gradual decline in global grain prices. But considering the agreement’s fragility, grain markets are unlikely to return to normal immediately.