It is now generally admitted that the rights and duties of neutrals in time of war are correlative. It was formerly claimed that the denial or grant of the same privileges to both belligerents constituted neutrality. Such a doctrine of neutrality might make it possible for a state to deny all the privileges which the first party to the war would especially need and which the second might not need, and to grant those privileges which the second might need and which the first might not need. It was seen that such a position was not neutral in fact, if sometimes so called. Gradually a more equitable view has come to prevail. Neutrality is at present held to demand “an entire absence of participation, direct or indirect, however impartial it may be.”

The state is responsible for the observance of neutrality within its sphere of competence. The state is responsible for its own action or failure to act where its jurisdiction can reasonably be exercised. The neutral state cannot be required to assume the burdens of prosecuting the war, however. If certain articles are declared contraband of war, the belligerent making the declaration cannot claim that the neutral state is under obligation to prevent its merchants from shipping such articles from neutral ports in the way of ordinary trade. To demand that the neutral prevent the sale of many articles included within the lists of contraband would be to put the burden of enforcing a belligerent's declaration upon the neutral, and this at the expense of the neutral's trade.