Solidarity between the Member States of the EU is mostly called upon during times of crisis, as also now during the Covid-19 pandemic. In this article, the definition and importance of solidarity is studied with a focus on the internal market. It appears that solidarity does not have one unequivocal meaning, but that its importance and value depend per EU policy area. Yet, it is noteworthy that elements of reciprocity and altruism lie at the core of the value. In the context of the internal market, the principle is not referred to in the specific Treaty provisions on the fundamental freedoms. However, solidarity and the idea behind it can be enforced through the principle of loyalty within the meaning of Article 4(3) TEU. The reaction of the Union and the Member States to the Covid-19 outbreak illustrates how solidarity is reflected during crises. Studying the recent actions seems to confirm the conclusion that solidarity within the single market is rather a political aspiration, that is not legally binding or enforceable by itself. However, one could argue that this requires change, since it follows from the current pandemic that solidarity is crucial for the resilience of the internal market in times of crisis. The principle of loyalty can indeed play an instrumental role here and can be used to enforce the objectives of solidarity. © 2021. The Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International License (CC-BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. See http://creativecommons.org/licenses/by/4.0/.

中文翻译：

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欧盟团结，以 Covid-19 危机为例

在危机时期以及现在在 Covid-19 大流行期间，最需要欧盟成员国之间的团结。在本文中，研究了团结的定义和重要性，重点关注内部市场。团结似乎没有一个明确的含义，但其重要性和价值取决于每个欧盟政策领域。然而，值得注意的是，互惠和利他主义的元素是价值的核心。在内部市场的背景下，该原则在条约关于基本自由的具体条款中未提及。然而，团结及其背后的理念可以通过第 4 条第 3 款 TEU 含义内的忠诚原则来实施。欧盟和成员国对 Covid-19 爆发的反应说明了在危机期间如何体现团结。研究最近的行动似乎证实了一个结论，即单一市场内的团结是一种政治愿望，它本身不具有法律约束力或可执行性。然而，有人可能会争辩说，这需要改变，因为从当前的大流行来看，团结对于危机时期内部市场的弹性至关重要。忠诚原则在这里确实可以发挥重要作用，并且可以用来实现团结的目标。© 2021。作者。这是一篇根据知识共享署名 4.0 国际许可 (CC-BY 4.0) 条款分发的开放获取文章，允许在任何媒体中不受限制地使用、分发和复制，前提是注明原始作者和来源。请参阅 http://creativecommons.org/licenses/by/4.0/。