Post-Brexit, UK is now reliant on EU goodwill for its security

The UK and the EU's internal security measures are premised upon political will, evidenced through the TCA's lack of codification.

Issues over the Northern Ireland Protocol put internal security arrangements at risk. The TCA allows both parties to amend the agreement according to changing needs through greater operational and strategic co-operation. If political will is impacted by the issue with Northern Ireland future co-operation is at further risk, preventing increased capacity in internal security for both the UK and the EU.

Additionally, cooperation is important in mitigating the potential challenge in the relationship regarding regulatory standards.

The UK now relies on adhering to EU regulations regarding internal security, particularly data protection standards for exchanging criminal data, attaching importance to effective co-operation between leading police and judicial practitioners in each security agency.

Regulatory divergence in the field of internal security is threatening, given the operational importance of UK-EU cooperation. Post-Brexit, the UK still must conform to EU data protection standards if it wishes to continue sharing data, information, and intelligence via the terms already agreed.

There have been suggestions the UK intends to reform elements of the data protection rules inherited from the EU, potentially leading the EU terminating the relevant internal security agreements (and therefore removing access to relevant data operations), since high data standards represent core constitutional right, again risking internal security capacity of both the UK and the EU.

'Significant operational losses'

Although the major positive from the agreement is operational, as the UK has retained access to Prüm decisions (and can opt into future extensions), PNR (Passenger Name Records), and ECRIS (European Criminal Records Information System) mechanisms, the TCA represents a damaging deal for the UK.

It has incurred significant operational losses which diminish its influence over European security architecture.

Notably, the EU denied the UK access to the Schengen Information System II (SIS II), the most widely used and largest information sharing system for security and border management in Europe.

Via SIS II, national security agencies provide 'alerts' on wanted and missing persons, lost or stolen property, and entry bans; and is immediately and directly accessible to all police officers at street level and other law enforcement authorities. The third-highest user, the UK used SIS II 603 million times in 2019.

Post-Brexit, the UK has lost access to 40,000 alerts for arrest or surrender, showing the value of the U.K. to Europe's internal security capacity, through EU's data-sharing operations.

Understandably, the EU rejected the UK's requests for SIS II access to safeguard the legal framework underpinning state membership, accepting UK membership would create a dangerous precedent of allowing a 'third party' country access to an EU institution despite rejecting necessary membership, in this case of Schengen.

Instead, the UK relies on Interpol's I-24/7 database, whose warning notices (equivalent to SIS II alerts) are processed manually within the UK's International Crime Bureau prior to reaching front-line policing, meaning time delays and increased resource needs. It also lacks real-time data alerts, leaving the UK dependent on the good will of EU member states to 'double-key' data into both systems (requiring extra effort on their part).

Such reliance represents not only the operational weakening of UK internal security, but also the UK's loss of influence in a field it previously had significant influence over.

Bye bye Europol and Eurojust

Furthermore, the UK has lost membership of Europol and Eurojust, the EU's Agencies for Law Enforcement Cooperation and for Criminal Justice Cooperation.

UK contact points have been stationed in each agency but the UK has ceased to take part in any institutional decision-making, administration or management, and will no longer play any part in shaping the future development of institutions it remains reliant upon.

Previously, the UK was a leading voice at Europol Management Board, with civil servant Sir Robert Wainwright serving as director of Europol between 2009-2018, and the second-largest contributor to Europol information systems.

Losing institutional influence, Wainwright argues that informal cooperation is critical for the UK, with the TCA outlining a basis of co-operation to be built upon, further exemplifying the potential risk the loss of political will could cause.

Ultimately, Brexit has curtailed Britain's role within European internal security, presenting new risks.

The greatest impact comes from the loss of British influence and the newfound reliance on informal influence and the goodwill of its European counterparts. The security provisions in the TCA mitigate risk, however fail to fully ensure the continued mutual benefit from shared internal security practices, with the EU needing to protect its own legal framework.

Instead, Britain must expand upon the cooperative measures of the TCA, attempting to retrieve (some of its) lost influence, ensuring operational harmony through national contact points and improving I-24/7.

Whilst potential divergence on regulatory data standards and the increasing friction arising from the Northern Ireland Protocol evidences how the UK is risking greater benefit for post-Brexit European internal security.

Irrespective, the UK government sees the TCA as a success, with the best possible agreement according to each sides red lines, as Britain refused to accept any role of the ECJ.

Such a perception emphasises how British attitude has changed, acknowledging weakened influence and operational limitations as success in an area it previously held significant influence. Britain must increase co-operation whenever possible to prevent further damage to internal security, maintaining political will and abiding by EU regulations.