Verification is a mechanism or procedure that seeks to determine whether a party is abiding by or fulfilling its obligations under a given agreement, and to detect those who violate their obligations. The essential basis of verification is a formal commitment by parties to engage, or not to engage, in certain activities. Verification has traditionally been associated with international security-related agreements. On-site inspections , usually by international inspectors. Monitoring of items, areas, or activities.
Satellite imagery is another important type of monitoring.
Evaluation of the information generated by the above activities, in order to make a judgement whether there is credible evidence indicating that the inspected party is or is not in compliance with the given agreement. Verification is often carried out using a combination of some or all of these mechanisms, referred to as a verification regime . Verification regimes of some non-proliferation treaties are described in the table below. It should be noted that uncertainty is inherent in verification. No practical set of verification measures can provide absolute assurance that a given party is or is not violating a given agreement.