However, “as long as the danger of war persists and there
is no international authority with the necessary competence and
power, governments cannot be denied the right of lawful self-de
fense, once all peace efforts have failed.”
The strict conditions for
legitimate defense by military force
require rigorous consideration. The gravity of such a decision
makes it subject to rigorous conditions of moral legitimacy. At one
and the same time:
the damage inflictedby the aggressor on the nationor community
of nations must be lasting, grave, and certain;
all other means of putting an end to it must have been shown to
be impractical or ineffective;
there must be serious prospects of success;
the use of arms must not produce evils and disorders graver than
the evil to be eliminated. The power of modern means of destruc
tion weighs very heavily in evaluating this condition.
These are the traditional elements enumerated in what is called
the “just war” doctrine.
The evaluation of these conditions for moral legitimacy
belongs to the prudential judgment of those who have responsibil
ity for the common good.
Public authorities, in this case, have the right and duty to
impose on citizens the
obligations necessary for national defense.
Those who are sworn to serve their country in the armed
forces are servants of the security and freedom of nations. If they
carry out their duty honorably, they truly contribute to the com
mon good of the nation and the maintenance of peace.
Public authorities should make equitable provision for
those who for reasons of conscience refuse to bear arms; these are
nonetheless obliged to serve the human community in some other
The Church and human reason both assert the permanent
validity of the
moral law during armed conflict.
“The mere fact that
war has regrettably broken out does not mean that everything
becomes licit between the warring parties.”
79 § 4.
79 § 5.
79 § 3.
79 § 4.