These are elementary rules which the Liberal must observe in all cases where his conduct is to be determined by nothing out of his own control. In other cases he can often do very little, and is compelled to acquiesce in conduct of which he would never himself be guilty. Here it is his duty to do as much as he can, to avoid the offensive imposition of his own ideas upon his fellows, to avoid arrangements which dispose of the fortunes of weak peoples irrespective of their wishes, to work in concert, not with one Power or group of Powers, but with all who are interested, and, in case of difficulty, to throw his weight into the scale with those whose aims most resemble his own. Generally, it is his duty to substitute the expression of moral rules by arbitration for the brutal assertion of national egoism in war. But there is no general presumption against war. It is always an evil. But it may be the least of possible evils. War for the independence of his own nation requires no justification. War for the independence of another nation or for the defence of some rule of international morality is to be judged by its expediency. "It seems to be impossible to state the principle of non-intervention in rational and statesmanlike terms, if it is under all circumstances, and without qualification or limit, to preclude an armed protest against intervention by other foreign Powers. There may happen to be good reasons why we should on a given occasion passively watch a foreign Government interfering by violence in the affairs of another country. Our own Government may have its hands full; or it may have no military means of intervening to good purpose; or its intervention might in the long run do more harm than good to the object of its solicitude. But there can be no general prohibitory rule. When a military despot interferes to crush the men of another country while struggling for their national rights, no principle can make it wrong for a free nation to interfere by force against him. It can only be a question of expediency and prudence."[8] In other words, the importance of the moral rule involved must be weighed with the chances {18} of success, the cost of war, the waste of life and wealth, and the sufferings of the poorer classes, which are the inevitable consequences of war. In the face of a universal enemy like Napoleon a war on behalf of Spain and Portugal was just. The Crimean War and the Boer Wars were unjust. Wars on behalf of Poles or Finns against Russia or Hungarians against Austrians would have been just, but not expedient, because no maritime power could have waged them with any chance of permanent success. It is a matter of calculation, and there are few wars, other than wars for the independence of their own country, which Liberals would not hold to cost more in blood and treasure than the principle for which they were undertaken.