Opinion of the Court
Paul W. Brosman, Judge:The accused, Heims, was convicted, following trial by general court-martial in Korea, of the willful disobedience of a lawful order of a superior noncom-missioned officer, in violation of Article 91, Uniform Code .of Military Justice, 50 USC § 685. The conviction was approved by the convening authority, and has also been affirmed by a board of review in the office of the The Judge Advocate General, United States Army. On petition of the accused, this Court granted further review, limited to-the following two questions:
“1. Whether the law officer improperly restricted cross-examination of prosecution witness McKenzie.
“2. Whether the law officer was required to instruct the court on physical ability to obey the order.”
We shall consider initially the second of these questions.
II
Is physical inability to carry out a military order a defense to a charge of willful disobedience of the order in question? We are aware of no provision of the Manual - for Courts-Martial, United States, 1951, which deals with the problem directly and explicitly, nor has our attention been directed to any by counsel. However, we are sure that it must be so considered — for, if the recipient of an order is in fact unable to comply therewith, he cannot be deemed to have evinced that “intentional defiance of authority” at which the proscription of the statute is directed. Manual, supra, paragraphs 1696, 170a. See Winthrop, Military Law and Precedents, 2d ed., 1920 Reprint, page 572. Incapacity, of course, may be— to some extent, at least— a matter of degree. In the case of a soldier directed to dig a ■ ditch, would he- — to escape responsibility for disobedience by reason of some physical shortcoming — be required to show, say, the loss of both hands ? Certainly not. Inability in such a setting must, we think, be weighed in the balances of reasonableness. This approach would of necessity require consideration, not only of the fact and extent of the injury, but as well of its relation to the task imposed, or other subject matter of the order, together with additional relevant circumstances, if any. Whether one may —in law and fact — be physically unable to comply with an order will vary somewhat, we believe,- with the pressing nature of the circumstances involved. In view iof this essential element of reasonableness, it seems impossible to formulate a general rule for application to all cases. Perforce each must rest largely on the conclusions of the triers of fact, reached after a consideration of all of the evidence presented, together with the realities of the situation as evaluated by rational military persons, and against a background of the transaction’s total setting. Because of the stern necessity for preserving discipline in the armed services, the proper application of this test of moderation must include not merely the question of whether the accused, under all of the circumstances, acted reasonably, but in addition, whether the balance of his judgment in the premises was clearly demonstrable — only a dif-*421ferenee in degree perhaps, but a selective and important one.
We now direct our attention to the question of whether the law officer here was required — in the ab- sence of specific request— to furnish the court with appropriate instructions on the affirmative defense of physical incapacity. Assimilating the present problem to our treatment of others involving affirmative defenses and related matters, we do not hesitate to say that such instructions are required suit sponte where the presence of physical incapacity is fairly raised by the evidence. United States v. Ginn, 1 USCMA 453, 4 CMR 45, decided July 10, 1952; United States v. Miller, 2 USCMA 194, 7 CMR 70, decided February 13, 1953.
It has been suggested that an instruction of this nature is necessarily included within one to the effect that the disobedience charged must have been willful. That is to say, a reasonable court-martial would inevitably refuse to find an act of disobedience to have been willful, if it was shown that the accused was physically incapable of compliance. However, this suggestion is opposed to the rationale of the decisions of this Court in previous analogous cases. We have declined, for example, to hold that an instruction having to do with specific intent necessarily requires evaluation of the effects of intoxication, and have ruled that the latter must be the subject of separate and specific instructions, if reasonably raised, despite its extremely close relationship to the matter of intent. United States v. Miller, supra, and cases there cited. Likewise, we have held that an instructional reference to “cowardly conduct” in a case involving a violation of Article 99 of the Code, supra, is insufficient to apprise the court-martial that it must be established that the actions of an accused were the product of fear. United States v. Soukup, 2 USCMA 141, 7 CMR 17, decided January 23, 1953. It is quite true that there is to be found in our opinion in United States v. Stout,. 1 USCMA 639, 5 CMR 67, decided August 27, 1952, certain broad language inconsistent with our present holding. However, it is clear that the question involved here was not before us under the issues of that case. Stout’s petition was granted that we might consider two matters only: (1) the sufficiency of the evidence and (2) the possible presence of a lesser included offense. In the present case one of the specific issues was “Whether the law officer was required to instruct the court on physical ability to obey the order.” Moreover, the evidence in the Stout' case fell far short of raising the existence of genuine physical incapacity on the part of the accused, and we so held. For this reason, the language used there was wholly unnecessary to the determination of the case. Consequently, now that the question is before us, and its resolution is necessary to our decision, we feel entirely free to examine the subject anew.
The issue then becomes one of whether the defense of physical inability was fairly raised by evidence in this case. We do not hesitate to say that it was. The order issued accused by an Army sergeant required that he tie sandbags. The accused testified that he warned the sergeant that he could not comply by reason of an injured hand. It was established that he had, in truth, received a substantial hand injury some eight days before the date of the incident in question, when a shell exploded as he was engaged in cleaning a machine gun. . The fact, nature, and extent of the injury were the subjects of extensive medical testimony. There was evidence, on the one hand, that accused was able to perform certain undiscrim-inative sorts of duty, but that he was unable to accomplish tasks requiring manual dexterity, coordination, and precise manipulation. On the other, there was testimony to the effect that he failed signally to assign his injury as the reason for the refusal to tie the sandbags. In addition, there was evidence tending to show that he could, in fact, perform this particular chore with competence: These conflicts in the evidence, however, raise problems of credibility beyond the province of this Court. United States v. Slozes, 1 *422USCMA 47, 1 CMR 47, decided November 20, 1951; United States v. Strong, 1 USCMA 627, 5 CMR 55, decided August 27,1952; United States v. Stewart, 1 USCMA 648, 5 CMR 76; decided August 29, 1952. Accused’s testimony —and especially as corroborated, even in part — was sufficient indeed to raise squarely the issue of physical incapacity. United States v. Simmons, 1 USCMA 691, 5 CMR 119, decided September 26, 1952. His story was not inherently improbable certainly, and the fact that there was contradictory evidence did not destroy - its evidentiary value. We conclude, therefore, that the law officer’s failure to instruct appropriately as to the legal consequence of physical disability under the instant charge was error. Manifestly, too, this failure was prejudicial to the substantial rights of the accused, and requires that the conviction be set aside and that a rehearing be ordered.
Ill
The remaining question relates to the scope of cross-examination, in trials by court-martial. At the present trial, the sergeant who issued the order in suit was called as a witness- for the prosecution. As such, he testified to the fact that the order was given, and that the accused refused to obey. it. The witness said nothing of the assignment of a reason by the accused for his refusal. On cross-examination, defense counsel elicited from the sergeant an admission to the effect that the accused had, in fact, said that he could not comply with the order — in contrast to the witness’ previous testimony showing that accused had said that he would not conform thereto. The sergeant then proceeded to relate that accused ascribed as his reason for refusal to assist in sandbagging the commanding officer’s bunker, the fact that the latter had not assisted the accused in the construction of his own — that .is, accused’s — bunker. Thereupon, defense counsel, through appropriate interrogation, drew from the sergeant a • statement that he was aware of the injury to accused’s hand. At this point, trial counsel objected on the ground of immateriality. The law officer observed that defense counsel had exceeded the scope of the direct examination, and required that he abandon the line of questioning then being followed. It is to be noted, however, that the law officer at the time carefully advised defense counsel that it was open to him to call the sergeant subsequently as his own witness.
The permissible scope of cross-examination has been the subject of frequent judicial expression by Federal courts, as well as by those of the several states. Inevitably, conflict and confusion has resulted in generous degree, but a definite trend of decision and thinking is clear. Viewed functionally, the basic rule, in essential form, must of necessity be that cross-examination is limited to the scope of the direct. That is to say, on cross-examination a witness may not be questioned with respect to matters not brought out — opened up— upon direct. Applied too strictly, this approach has often resulted in unnecessary reversals, and has developed needless delays and inconvenience at trial, not infrequently hampering the primary purpose of the hearing — the development and testing of all relevant facts. At the other swing of the pendulum is the rule — followed today in a sharply limited number of jurisdictions, but frequently advocated by text writers — that the cross-examiner should be allowed the widest possible latitude in questioning — even to the point of permitting the introduction of one’s own case during the testing period. However, this view, in seeking to remedy the deficiencies of the stricter form of the “scope-of-the'-direct” rule, has itself often led to abúse, and — although administratively defensible — is certainly dubious as a matter of theory. As is so frequently the case, the most desirable rule, we believe, lies somewhere between the two poles — and is the very one made manifest in the better reasoned Federal decisions and in paragraph 149& of the Manual, supra:
". . . Cross-examination of a witness is a matter of right. • It should, in general, be limited to the issues concerning which the witness *423has testified on direct examination and to the question of his credibility. Counsel often cannot know in advance what pertinent facts may be brought out on cross-examination and for that' reason it is to some extent exploratory. Reasonable latitude should be given the cross-examiner, even though he is unable to state to the court what facts his cross-examination is intended to develop. Leading questions may be used freely on cross-examination.
“The extent of cross-examination with respect to a legitimate subject of inquiry is within the sound discretion of the court.” (Emphasis supplied).
The principal part of this language was, it appears, adopted verbatim from the opinion of the Supreme Court in Alford v. United States, 282 US 687, 691-692, 75 L ed 624, 627, 51 S Ct 218. That the extent of cross-examination is a matter resting largely within the sound discretion of the trial judge is now widely accepted among those jurisdictions following the “seope-of-the-direct” rule. Glasser v. United States, 315 US 60, 83, 86 L ed 680, 706, 62 S Ct 457. It is, of course, the view specifically enjoined in paragraph 1496 of the Manual quoted, supra. Through it, we believe, there may be achieved thé- soundest solution to the problem, which is, in the last analysis, principally one of trial administration. The trial judge — or the law officer in the military scene — is present personally at the nisi prius hearing. He is aware of the need for an orderly procedure, and also of the convenience of the parties, plus the practical and juristic demands of the particular situation. Moreover, he is and must be the genuine head and guiding spirit of the tribunal.
Had we been sitting as law officer in the case at bar, we might well have ruled as he did — or indeed we might, on the other hand, have permitted de-' fense counsel to continue the line of questioning outlined earlier. From the bald pages of the record, we are inclined to believe that the interest of an orderly procedure and the highest purposes of the trial would have been served by permitting the sergeant’s cross-examination to continue. However, this is quite beside the point, and by no means requires that we hold that the law officer abused his discretion in ruling in the manner he did. If the exercise of sound discretion means anything, the law officer here did not err. It should be observed, too, that he specifically advised defense counsel that he might recall the witness as his own at an appropriate time)
For the reason assigned' in Part II, supra, the decision of the board of review must be reversed and a rehearing ordered.
Chief Judge Quinn concurs.