Few political decisions have weakened the European Union as much as Angela Merkel’s opening of her country’s borders in 2015.

Back then, the German Chancellor unilaterally decided to allow millions of refugees stranded in Hungary to move into the bloc, triggering severe tensions between EU members.

After that traumatic experience, it is surprising to see Merkel repeating her migration unilateralism after a fire in the refugee camp of Moria on the Greek island of Lesbos.

In case you missed the news from Moria, this is what happened. Across the Greek islands, according to UNHCR, some 27,000 people live in refugee camps. Almost half (47 percent) are from Afghanistan, 19 percent are from Syria and the remainder hail from mainly Middle Eastern or African countries.

The camps, and especially Moria, have been a humanitarian disaster zone – and frankly a disgrace for Europe. Overcrowding is so bad that refugees do not even have regular and safe access to food or water (apparently there is one tap per 1300 people). Sanitation conditions are disastrous, and Human Rights Watch has long pointed out that these places are unliveable, particularly for the 31 percent of refugees who are children.

The camps were meant to facilitate the processing of refugees’ asylum claims so they could either properly enter the EU or be turned away. However, in practice these administrative processes take months or even years. In the meantime, refugees are kept in conditions that one would not expect to see anywhere in Europe.

The treatment of asylum seekers on the Greek islands is inhumane and may also be a violation of international law which sets minimum standards for the treatment of refugees. This is an inexcusable failure of the Greek authorities and, by proxy, the EU.

In this sense, the pent-up frustration among the refugees trapped in Moria is understandable. Two weeks ago, it erupted into violence as some refugees burnt down the camp. More than 12,000 refugees became homeless after the fire.

The fire created a moral dilemma. How should Europe respond to this humanitarian disaster? After years of neglecting the issues, there was probably an element of guilt involved which spurred some politicians into action, not least the German chancellor.

Immediately after the fire and under pressure from public opinion, Merkel began arguing for a “European solution.” The member states of the European Union should accept contingents of the now tentless refugees from Moria.

The response, however, was the same that Germany had in the big refugee crisis of 2015. Few European countries are prepared to follow the German lead.

The Scandinavian countries tried to stay out of the issue, while Austria, Poland and Hungary made their positions clear: They do not accept responsibility and will not accept any new refugees.

The Eastern Europeans have both the law and logic on their side. Clear rules govern how and where asylum seekers can make their claims. Under the EU’s Dublin Regulation, first approved in 1990, a member state receiving an asylum request must process it. Other member states are not obliged to get involved. In this case, the Moria disaster is considered Greece’s problem.

Beyond this legal argument, the Eastern Europeans also fear that a deviation from the Dublin arrangement would set a bad precedent for other prospective migrants. It would be like giving every refugee at the border a box of matches to circumvent the rules and skip the migration queue.

From Merkel’s point of view, pictures of desperate refugees in inhumane camps are intolerable. Which is the same emotion that motivated Merkel to open Germany’s border in 2015.

Still, her unwillingness to procedurally deal with the humanitarian disaster is driving the EU further apart – and it signals to would-be migrants and their traffickers that crossing the EU border is once again worth a try.

This crisis has no good solution. In an ideal world, the EU’s border force would prevent refugees from entering. If that cannot be achieved, those refugees reaching European soil would be housed in humane detention camps. Their claims would then be processed quickly, and unsuccessful applicants would be sent home. For the remainder, the EU would help ease the burden on peripheral countries like Greece, Italy or Spain, where migrants typically first present themselves.

Unfortunately, the EU’s border force cannot prevent border breaches. The refugee camps are hell holes. The processing takes forever. And there is no EU-wide solution for better reprocessing.

Merkel’s response to the latest refugee crisis only makes sense in the ideal-world scenario. In the real world, her unilateralism (understandable as it is) is dividing the EU and encouraging human traffickers.

In short, Merkel repeats her 2015 mistake. And she does so at a time when Germany holds the EU presidency.

It is a tragedy for everyone involved: Merkel, the EU – and, of course, those migrants stranded in Moria. You must be heartless not to feel for the children stranded in such ghastly circumstances.

And yet, helping those children would automatically ensure that other children will meet the same fate later.

The EU’s refugee policy is stuck between rocks, hard places and burnt detention camps.