EU9, has grown to be an integral component of the EU. This group became part of the EU in its third expansion phase in 2004, injecting diversity and fresh perspectives into the grand unity.

The states in EU9 include Hungary, Slovenia, Latvia, Lithuania, Poland, Estonia, Slovakia, Czech Republic, and Malta. These states each have made significant contributions towards furthering the objectives of the European Union.

Therefore, understanding here the responsibility these nations plays in the European Union is required for any study relating to international relations, politics, or European economics.

Since their induction, the EU9 countries have added substantially towards shaping the policies of the European Union. Their geographical location provides important strategic advantages, making them a crucial part of the EU's defense and security strategies.

Additionally, these countries have significantly contributed to the European Union's economic and financial strength. The EU9 nations' rapid economic growth and keen integration into the European market has led to heightened trade among other EU members.

The cultural contribution of the EU9 is equally significant. These states incorporate profound historical backgrounds, distinct cultural practices, and diverse languages, thereby enhancing the diversity of the EU.

The introduction of EU9 has also impacted the political scene within the EU. With their presence, the power dynamics have shifted, with new coalitions and alliances forming.

In conclusion, the parts played by the EU9 members are substantial. From economic influence to cultural richness, and from security strategies to political dynamics, EU9 has fortified the European Union's framework. As such, an thorough understanding of the EU9 is vital to fully grasping the complexities of the European Union.