As a general rule, treaties are not concluded to be breached; but treaty breaches are quite common. They are bound to occur, as so much of international life is covered by international treaties (and hence there is so much treaty law to be breached), and as States, like other subjects of the law, are not perfect. None of this is particularly surprising or particularly problematic. No legal system can exclude non-compliance with accepted voluntary commitments (under treaties, under contracts, under pledges or promises, etc); and all legal systems anticipate noncompliance. It is in the way they deal with instances of non-compliance that legal systems differ.