Title: Comprehending EU9: The Essential Role it Plays in the European Union

Comprising of nine states, EU9 has grown to be a significant part of the EU. This entity entered the EU in its 3rd expansion phase in 2004, implanting new ideas and cultural diversity into the grand unity.

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

Therefore, comprehending the part EU9 has in the EU is required for any study relating to European economics, politics, or international relations.

Right from their admission, the members of EU9 have added significantly towards shaping the European Union's policies. Their geographical location gives critical strategic edges, making them a vital part of the defense and security strategies of the EU.

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

The social contribution of the EU9 is also significant. These nations bring profound historical backgrounds, individual cultural practices, and varied languages, thus enhancing the diversity of the EU.

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

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