The European Commission, the EU's executive body, on Friday circulated a progress report on the advancement of security priorities and commitments made under European Commission President Jean-Claude Juncker.

The report suggests the executive body made significant advances towards a "Security Union," noting achievements in combating terrorism and strengthening the bloc's external borders, including the creation of a transnational counterterrorism center and border guard force.

"We criminalized terrorism and foreign fighters across the EU, we cracked down on the use of firearms and on terrorist financing, we worked with internet companies to get terrorist propaganda offline and we fought radicalization in Europe's schools and prisons. But there is more to be done," Juncker said in September during his State of the Union address.

While the EU has witnessed a greater push for cooperation on internal security in the wake of deadly attacks in European capitals, upending the bloc's "existential crisis" following mass irregular migration and the so-called "Brexit" does not solely rest in combating terrorism, despite the European Commission's chief priorities outlined in the progress report.

'Long time to come'

Andrea Frontini, policy analyst at the Brussels-based European Policy Center (EPC), told DW that although the focus on internal security has been used by the Commission as a prospect for greater European unity, the wider project of integration faces significant challenges.

"The European Commission has been nimbly exploiting the heightened political priority assigned to internal security and the fight against terrorism by national policymakers across Europe, and it has taken this opportunity to encourage a stronger integrationist push at the political, operational and legislative level," Frontini said.

However, the "predominant member state-centered features of policies" and development of "EU-led harmonization of practices, regulations and processes" prove obstacles to further advancements towards a closer-knit Europe, the EPC analyst said.

"This will all require further efforts to streamline and synchronize European responses at all levels, and also calls for a viable and trust-based division of labor between the EU and member states in a policy domain which will largely remain a domaine reservé of national authorities for a long time to come," Frontini added.

Indeed, weeks after the Bratislava summit, which witnessed European leaders gather for a crisis summit in the wake of British voters' narrow decision to leave the bloc, little besides countering terrorism has solidified ambitions for a more united Europe.

The perils of refusing solidarity

With the likes of Poland and Hungary refusing to budge on the question of settling refugees under a bloc-wide relocation plan, tensions between member states have reached new heights, failing to concretize endeavors on a common asylum policy.

"The only way to keep some form of unity is to safeguard our external borders, and to better control who enters, when and under which conditions. This gives you an example of how difficult it is to move forward, because internal and external security are tied together," said Ronja Kempin, senior fellow at the Berlin-based German Institute for International and Security Affairs (SPW).

But deepening internal divisions pose a greater threat to the EU's prospects for integration than terrorism and migration, the veteran researcher said.

"We know that at a national-level alone, we are hardly able to confront all the challenges of the present moment, be it terrorism domestically or abroad, be it the migration crisis, be it the economic situation and the difficulties some member states face, such as cutting youth unemployment," Kempin said.

"If we continue to refuse solidarity for one another, I think this endangers us much more than any challenge that might come from outside," she noted.