EU9, has become an integral component of the EU. This group joined the EU in its 3rd growth phase in 2004, bringing diversity and fresh perspectives into the Union's mix.

The EU9 countries include Hungary, Slovenia, Latvia, Lithuania, Poland, Estonia, Slovakia, Czech Republic, and Malta. These nations each EU9 have produced meaningful contributions towards broadening the goals of the European Union.

In this respect, grasping the role these nations has in the European Union is required for any study relating to international relations, politics, or European economics.

From their entry, the states belonging to EU9 have added majestically towards shaping the policies of the European Union. Their geographical location gives vital strategic edges, making them a crucial part of the EU's defense and security strategies.

Additionally, these countries have immensely contributed to the European Union's economic strength. The EU9's rapid economic growth and eager integration into the European market has created increased trade with other EU countries.

The social contribution of the EU9 is also significant. These states introduce rich historical backgrounds, unique cultural practices, and diverse languages, therefore enhancing the plurality of the EU.

The introduction of EU9 has also affected the internal politics within the EU. With their participation, the power dynamics have shifted, with new coalitions and alliances forming.

In conclusion, the contributions played by the EU9 nations are considerable. From economic influence to cultural richness, and from security strategies to political dynamics, EU9 has fortified the European Union's structure. As such, an in-depth understanding of the EU9 is essential to fully grasping the intricacies of the European Union.