45 30. After its visits, the CPT drew up a number of guidelines, which it recommended the countries concerned to follow. In order to promote widespread application of these guidelines in all the States Parties to the Convention, the Committee has decided to group together the most important principles and comment on them below. Of course, what follows must be read in the light of a State’s fundamental obligation not to send a person to a country where there are substantial grounds for believing that he/she would run a real risk of being subjected to torture or ill-treatment. 31. The CPT recognizes that it will often be a difficult and stressful task to enforce a deportation order in respect of a foreign national who is determined to stay on a State's territory. It is also clear, in the light of all the CPT’s observations in various countries – and particularly from an examination of a number of deportation files containing allegations of illtreatment – that deportation operations by air entail a manifest risk of inhuman and degrading treatment. This risk exists both during preparations for deportation and during the actual flight; it is inherent in the use of a number of individual means/methods of restraint, and is even greater when such means/methods are used in combination. 32. At the outset it should be recalled that it is entirely unacceptable for persons subject to a deportation order to be physically assaulted as a form of persuasion to board a means of transport or as a punishment for not having done so. The CPT welcomes the fact that this rule is reflected in many of the relevant instructions in the countries visited. For instance, some instructions which the CPT examined prohibit the use of means of restraint designed to punish the foreigner for resisting or which cause unnecessary pain. 33. Clearly, one of the key issues arising when a deportation operation is carried out is the use of force and means of restraint by escort staff. The CPT acknowledges that such staff are, on occasion, obliged to use force and means of restraint in order to effectively carry out the deportation; however, the force and the means of restraint used should be no more than is reasonably necessary. The CPT welcomes the fact that in some countries the use of force and means of restraint during deportation procedures is reviewed in detail, in the light of the principles of lawfulness, proportionality and appropriateness.