The U.S. Army defines three classes of people who may present themselves:  A Soviet response, to someone visiting the embassy, was "This is a diplomatic representation and not an espionage centre. Be so kind as to leave the building or we will call the police". According to Suvorov, the police are usually not called but the embassy staff chase the would-be agent out quickly. Cautious handling of walk-ins was not exclusively a Soviet concern. U.S. Army procedure is to have military intelligence (MI) or military police (MP) personnel handle all aspects of walk-ins. Under U.S. Army Regulations, military police are not intended to do interrogations, which are the responsibility of military intelligence personnel. While serious discussion with the contact will be done by counter-intelligence specialists, information about the walk-in must be restricted to people with a "need-to-know." "The information the walk-in provides must be guarded and classified appropriately". While the interviewers will actually be from MI, the walk-in will never be told the identities of intelligence personnel. If they ask to see an intelligence representative, they will be told none is available. Both these measures are intended to prevent hostile intelligence services learning about the structure or procedure of US intelligence/counterintelligence personnel. The Soviets showed caution equivalent to the United States. Soviet GRU doctrine was that on general, a walk-in is considered only when they can show some evidence of access to valuable material. The best way of doing this is actually . Suvorov observes that "this is perhaps the only way to convince the GRU that they can trust the person". Suvorov describes an ideal; the one-time head of the GRU, Gen. Ivan Serov, was willing to explore potential agents who gave plausible information about themselves and their access, or a "write-in" whose potential could be verified before a meeting. It has been the general experience of intelligence agencies that potential recruits, recruits early in the development process, and those currently reporting to a local case officer, still need to be checked against master biographical and other files, which will help spot foreign counterintelligence. This counterintelligence interest could be from their own or third countries. Once an individual is seen to have potential access to information, the recruiting officer or staff considers why a presumably loyal and trusted individual might be willing to betray his own side. A basic set of reasons are the classic MICE motivations, with further insights in attitudes predisposing to cooperation.