Due to the unpredictable nature of lone wolf attacks, government officials and authorities often struggle to implement measures to prevent or address the issue effectively. However, certain approaches have been adopted in recent years to tackle the problem.The United States of AmericaThe United States of America has been one of the major countries that suffer from lone wolf attacks. They are also one of the leading countries in terms of counterterrorism. To address the issue, they have implemented measures such as hardening and expanding physical barriers around sensitive locations and critical infrastructures, improving security procedures and screening at airports and other entry points, tightening controls on people entering the country, and strengthening investigation and prosecution capabilities for terrorism-related cases. The United States’ Department of Homeland Security, which integrated all or part of 22 different federal departments and agencies to unify domestic counterterrorism efforts, collaborated with the Transportation Security Administration, which centralized and standardized airport security, to implement the aforementioned policies, with more than 260 government entities either created or reorganized to implement these reforms.The United States also invested large sums on countering terrorism abroad and building the capacity of partner security and intelligence services. Since the 911 event, the US Congress has appropriated an estimated $1.6 trillion in war-related operational costs and more than $43.5 billion in intelligence-related programs annually. The United States also has programs that limit the possession of explosives to only those with a legitimate need, making it far harder for terrorists to build bombs. Unfortunately for the US, expanding the policy to limiting guns is a political non-starter even in the means of countering terrorism.European UnionWith terrorists increasingly targeting public and crowded spaces, as shown by the recent attacks in Barcelona, London, Manchester and Stockholm, the European presented Action Plans to step up the support to Member States efforts to protect and reduce the vulnerability of public spaces. Measures implemented include increasing financial support for transnational projects to improve protection of public spaces and other security solutions, issuing guidance materials for Member States to upgrade public security infrastructures, establishing Practitioners’ Forum and setting up High Risk Security Networks to provide a platform for necessary trainings to improve preparedness, and creating an operators forum to deepen the cooperation between local actors and private sectors. Police and intelligence agencies considered and implemented physical options to protect against terrorism. For example, the UK parliament is surrounded by black barriers to prevent a high-speed attack, while the Emirates Stadium contains letters spelling “Arsenal” in concrete on the concourse, helping slow or stop an attack. Barricades have been installed on the city’s Waterloo, Westminster and Lambeth bridges and obstructions are being put in place to bolster security at Christmas markets during the holiday season. Paris, on the other hand, announced plans to extend the security perimeter around the Eiffel Tower to include public gardens on the iconic landmark’s western and eastern sides and a “bulletproof fence” around the other perimeters. Other countries in Europe that have been targets of vehicular-terror attacks, have also ramped up their security measures and set guidelines on how to better protect citizens.United NationsThe United Nations General Assembly adopted the Global Counter-Terrorism Strategy in 2006. The strategy is a global action to enhance national, regional and international efforts to countering terrorism. Through its adoption, it meant that all Member States have agreed to a common strategic and operational approach to fight terrorism, measures including strengthening state capacity to counter terrorist threats to better coordinating United Nations system’s counter-terrorism activities. The General Assembly also reviews the Strategy every two years, making it a document that is constantly updated to adapt to Member States’ counter-terrorism priorities. There are four pillars in this overall strategy:1. Addressing the conditions conducive to the spread of terrorism: including promoting cultural peace, dialogues, and conflict preventions, etc.2. Measures to prevent and combat terrorism: including prohibiting terrorism-related activities, encouraging cooperation to fight terrorism, etc.3. Measures to build states’ capacity to prevent and combat terrorism and to strengthen the role of the United Nations system in that regard: including encouraging various UN organizations to cooperate with Member States, etc.4. Measures to ensure respect for human rights for all and the rule of law as the fundamental basis for the fight against terrorism: including reaffirming and implementing existing resolutions, as well as work with related organizations to monitor the maintain fundamental human rights while implementing anti-terrorism measures, etc.Lone wolf attacks are essentially unpredictable, while they can be reduced through aforementioned means, it is unlikely that total elimination will occur through these solutions. Past actions focused more on preventing lone wolves from initiating an attack through reducing weapon accessibility and raising security, however it is still possible for them to find other ways to conduct terrorism. UN resolutions, on the other hand, attempts to stop the spread of terrorism ideologies while fighting them at the same time. However, these measures focused on preventing general terrorism acts rather than individual behaviors. Thus, the topic needs further investigation or discussion to maximize the effectiveness of preventing lone wolf terrorism acts.