What is the test for an action against a defendant in a transaction outside of the United States?

In the. Machado v. Pontes Case, supra, at p. 234 ([1897] 2 Q.B.) Rigby, L.J. states: Willes, J., in Phillips v. Eyre, [supra] was laying down a rule which he expressed without the slightest modification, and without the slightest doubt as to its correctness; and when you consider the care with which the learned judge prepared the propositions that he was about to enunciate, I cannot doubt that the change from “actionable” in the first branch of the rule to “justifiable” in the second branch of it was deliberate. The first requisite is that the wrong must be of such a character that it would be actionable in England. It was long ago settled that an action will lie by a plaintiff here against a defendant here, upon a transaction in a place outside this country. But though such action may be brought here, it does not follow that it will succeed here, for when it is committed in a foreign country, it may turn out to be a perfectly innocent act according to the law of That country and if the act is shown by the law of that country to be an innocent act, we pay such respect to the law of other countries that we will not allow an action to be brought upon it here. The innocency of the act in the foreign country is an answer to the action. That is what is meant when it is said that the act must be “justifiable” by the law of the place where it was done.