In the past, espionage activity was typically directed towards obtaining political and military intelligence. These targets remain of critical importance but in today's technology-driven world, the intelligence requirements of a number of countries are wider than before. They now include communications technologies, IT, energy, scientific research, defence, aviation, electronics and many other fields. Intelligence services, therefore, are targeting commercial as well as government-related organisations. They sometimes do this on behalf of state-owned or sponsored companies in their own countries.
The UK is a high priority espionage target. Many countries actively seek UK information and material to advance their own military, technological, political and economic programmes. The threat is not confined to within the UK itself. A foreign intelligence service operates best in its own country and therefore finds it easier to target UK interests at home, where they can control the environment and take advantage of any perceived vulnerabilities. The most capable foreign intelligence services are able to operate all over the world.
Intelligence agencies are directed by their governments to focus their attention on specific priorities. State agencies, the military and companies working on sensitive technologies are prime targets for foreign espionage.
Intelligence services working against the UK tend to focus on gaining a number of different types of secret information.
These will include technical information about weapons, details of where troops are located, information on defences and so on. This can be especially useful to an enemy country in wartime. It can help an enemy to find weak points or launch surprise attacks. It can also be useful to terrorists, as it can help them to pick out targets and weak points.
These will include information on companies' products and plans. Spies are especially interested in details of new inventions that may be of military or commercial use. Examples include communications technologies, computers, genetics, aviation, lasers, optics and electronics. Such secrets may also help to give some countries an economic or military advantage.
These will include confidential information on political and security affairs, negotiating positions, sensitive economic information and details of policy developments. Foreign governments could use such information to gain advantage in areas such as international relations and intelligence operations.
Some foreign governments also target dissident movements and individuals that they see as a threat to their control at home. The UK's long tradition of political tolerance has meant that many foreign dissidents have made their homes here over the years - most famously the Russian revolutionaries Lenin and Trotsky - but this has also prompted the sometimes hostile interest of foreign intelligence services and this continues to the present day.