The arrival in Europe of well over a million people in 2015 seeking sanctuary or better lives sparked one of the 28-nation bloc's biggest political crises. Mediterranean coastal states felt abandoned by their partners as they struggled to cope. Others erected fences to keep migrants out.
Countries bickered over who should take responsibility and whether they should be obliged to help. A refugee-sharing quota scheme was challenged in court. The foundation of Europe's asylum system — that migrants must apply for asylum and stay in the country they first arrive in — remains a ticking policy time bomb that the EU has failed to defuse.
What has worked is money. Lots of it. Migrant entries into Europe have dropped to a trickle thanks to the much-criticized understanding it reached with Turkey. The EU has provided Turkey with around 3 billion euros ($3.4 billion), and could hand over 3 billion more, to help Ankara cope with Syrian refugees on its territory, plus other political and economic incentives.
The EU is trying to replicate different versions of that model with African countries like Egypt, Morocco, Niger and Tunisia that surround Libya; the conflict-torn country that has been the source of most people entering Europe.
In a draft of Thursday's summit statement, EU leaders say "that the number of detected illegal border crossings has been brought down to pre-crisis levels, and that the overall downward trend continues."
"This is the result of the external migration policy of the Union, based, in particular, on control of external borders," they will say, according to the text, which could still be modified. "This policy should therefore be continued, further developed and fully implemented. Vigilance on all existing and emerging routes should be maintained," they will say.
The fresh signal of determination to build a so-called Fortress Europe comes just as the EU border agency Frontex said Thursday that the number of people trying to reach European shores via the Mediterranean has dropped sharply this year due to fewer people leaving Libya for Italy. Around 138,000 people have entered to November, compared to same period last year, a drop of 30 percent.
That said, the numbers entering Spain so far this year have more than doubled over the same period in 2017. Almost 53,000 unauthorized migrants arrived there in the first 11 months of 2018. Most were from Morocco, Guinea and Mali.
Despite this, the leaders will also discuss preparations for an EU-Arab League summit to be held in Egypt in February; a first symbolic sweetener offered to President Abdel-Fattah el-Sissi, much the same as the EU did in 2015 for Turkish President Recep Tayyip Erdogan.
The EU hopes el-Sissi can be encouraged to use his coast guard to pick up migrants leaving Libya and take them back to the African mainland, ensuring they don't become Europe's responsibility.