 Counter-intelligence forms a large part of the section's remit, in addition to fulfilling counter-terrorist, counter-subversion, counter-insurgency, counter-sabotage roles, and physical security of critical infrastructure.The National Security Intelligence Section works very closely with the Garda SDU and Garda National Surveillance Unit (NSU) to spy on potential terrorism threats, particularly from Islamic terrorists and dissident republicans.Military Intelligence have a number of Arabic speakers in their ranks as a result of Defence Forces deployments overseas.