Faced with more than 1 million migrants flooding across the Mediterranean last year, European nations tightened border controls, set up naval patrols to stop smugglers, negotiated an agreement with Turkey to limit the numbers crossing, shut the Balkan route used by hundreds of thousands, and tried to speed up deportations of rejected asylum-seekers.
- Turkey tells EU: Provide visa-free travel or abandon migrant deal
- Pig heads on border fence would deter Muslim migrants, Hungarian official says
- Syrian refugees in Greece, depressed and desperate, regret leaving home
Yet many issues still remain.
European nations continue to squabble about whether, and how, to share the newcomers between them and the issues that drove refugees to Europe in the first place — such as Syria's unrelenting war — are unresolved.
Overall, 2,901 people have died or disappeared crossing the Mediterranean in the first six months of 2016, most along the dangerous central route to Italy — a 37 percent increase over last year's first half, according to the International Organization for Migration.
Here's a look at where things stand in key countries.
Turkey is hosting some 3 million refugees, including more than 2.7 million Syrians. Most refugees there don't get government support, but the agreement with the EU calls for the bloc to provide up to 6 billion euros ($6.8 billion) to help Syrian refugees in Turkey.
The deal also provides for one Syrian refugee from Turkey to be relocated to EU countries for each Syrian who arrives illegally in Greece and is sent back. So far only 1,152 have been resettled under the program — more than half of them to Germany and Sweden.
The numbers of migrants arriving in Greece have dropped dramatically since the March agreement with Turkey, but several thousand a month still make the journey, some 160,000 in the first half of this year.
Over 58,000 people remain stuck in the financially struggling country, most hoping to continue north to nations like Germany or Sweden. The majority have applied for asylum, hoping to be relocated among EU nations — but the program is moving at snail's pace amid fierce resistance from eastern and central European countries.
So far, only around 4,400 people have been relocated from southern Europe under a plan that's supposed to see 160,000 moved over two years through September 2017. Yet there's little Brussels can do to force any nations to comply.
New arrivals now are insignificant compared to 2015, but they have increased since the July 15 attempted coup in Turkey, topping 2,300 in the first three weeks of August. This is straining resources on the eastern Aegean Sea islands and the government has promised to build more housing on the mainland.
Fears are also growing that the EU-Turkey deal might fall apart as Ankara presses for the 28-nation bloc to allow its citizens visa-free entry.
About 70,000 migrants crossed the Mediterranean into Italy from January to June this year, similar to the same period last year. But with routes northward now restricted, there's nowhere for them to go and, as smugglers resort to more dangerous practices, more migrants are dying en route.
Migrants are sleeping in hotels, homeless shelters, train stations and tent camps. The Tuscan city of Capalbio is putting them in fancy villas and Milan is readying a jail to take in some.
Nigerians make up the biggest group of newcomers to Italy, followed by Eritreans, Gambians, Ivorians and Sudanese, according to the UN refugee agency.
The wave of arrivals is testing Italy's social services and Italian Premier Matteo Renzi's patience as he faces domestic resistance from the anti-immigrant Northern League and reluctance from Italy's EU partners to resettle asylum-seekers. To date, only 961 would-be refugees have moved out of Italy, according to the IOM.
Earlier this month, France returned to Italy some 200 migrants who plunged into the sea at the Ventimiglia border crossing. The latest hotspot is Como on the Swiss border. There authorities have approved a tent camp to house the estimated 300-500 migrants who have camped out at the train station after taking trains daily into Switzerland, only to be returned.
Germany has seen a much-reduced number of newcomers this year after taking in hundreds of thousands in 2015, the majority of those entering Europe.
Up to the end of July, 238,424 new arrivals were recorded — 92,000 of them in January, before the Balkan route was shut down. The figure has since leveled out at around 16,000 per month.
German Chancellor Angela Merkel has stuck to her insistence that Germany will give shelter to those who need it and that the country "will manage" the refugee crisis. That mantra has fueled ongoing strife in her conservative bloc, and benefited the nationalist, anti-immigration Alternative for Germany party.
Two attacks this summer by asylum-seekers that were claimed by ISIS have also fueled concerns.
Meanwhile, Germany has moved to tighten asylum rules, deport more rejected asylum applicants and turn more people back at the border.
Merkel has criticized other European countries' unilateral moves to shut the Balkan migration route at Greece's expense but was a leading advocate of the Turkey-EU agreement. She insists the deal remains necessary, despite tensions with Ankara over visa-free travel.
The discovery of 71 suffocated people in the back of a smuggler's truck in Austria a year ago triggered an outpouring of support for refugees. That now seems a distant memory.
Austria's former chancellor Werner Faymann urged Austrians to open their arms to the migrants, but faced increasing concerns that the country couldn't cope. Faymann changed course early this year, suddenly backing calls to shut Austria's border. He resigned in May amid falling support.
His successor, Christian Kern, has continued on the restrictive path welcomed by most Austrians, even as he urges them to be open-minded toward new arrivals.
Austria was the main force in the shutdown early this year of the Balkan route. After accepting more than 80,000 migrants last year, the country stands ready to turn back the first would-be refugee over the 37,500 limit it has set as a quota for 2016.
Serbia and Hungary
The flow of migrants into Serbia has diminished drastically but not dried up entirely.
Instead of thousands a day registering at organized centers, hundreds a day now try to enter illegally. Illustrating the dangers, a 20-year old Afghan migrant crossing illegally from Bulgaria was shot and killed this week by a hunter in an apparent accident.
Human Rights Watch says migrants and refugees at Hungary's border with Serbia are being forced back, in some cases violently.
UNHCR estimates that some 4,400 asylum-seekers are now stranded in Serbia, mostly since Hungary started enforcing new regulations in July that allow authorities to "escort" migrants and refugees caught within 8 kilometers (5 miles) of the border back to Serbia.
Two "transit zones" on the Serbian side now process around 30 asylum applications a day, while 1,000 or more people are waiting in poor conditions to file asylum claims, most of which are rejected.
Hungarian Prime Minister Viktor Orban has called migrants "poison" and said Friday that Hungary will build a new, "more massive" fence on its southern border to defend against a possible surge in numbers. A government-initiated referendum on October 2 is meant to rally political support against any EU plan to resettle migrants among the bloc's members.
Migrant numbers in Calais have soared this month, even though authorities shut down half of the city's wretched camp earlier this year, and the British and French governments erected security fences and announced measures to deter new arrivals.
The French government says the number of migrants in the makeshift Calais camp known as the "jungle" has reached its highest official level yet: 6,901. Aid groups say it's closer to 9,000.
This week, a Sudanese migrant died after a clash between groups of Sudanese and Afghans, the 11th migrant to die in Calais this year.