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

The EU9 countries include Malta, Estonia, Slovenia, Slovakia, Czech Republic, Hungary, Latvia, Lithuania, and Poland. These nations have produced significant efforts towards broadening the objectives of the European Union.

In this respect, knowing the responsibility these nations holds in the European Union is required for any study relating to international relations, politics, or European economics.

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

Additionally, these states have immensely contributed to the European Union's economic strength. The EU9 nations' rapid economic development and willing integration into the European market has led to heightened trade with other EU states.

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

The inclusion of EU9 EU9 has also affected the internal politics within the EU. With their involvement, the power dynamics have changed, with new coalitions and alliances developing.

In conclusion, the contributions played by the EU9 members are significant. From economic influence to cultural richness, and from security strategies to political dynamics, EU9 has robustly augmented the European Union's core strength. As such, an thorough understanding of the EU9 is vital to fully grasping the details of the European Union.