Two fundamental tenets of international humanitarian law are those of “civilian immunity” and the principle of “distinction.” They impose a duty to distinguish at all times in the conduct of hostilities between combatants and civilians, and to target only the former. It is forbidden in any circumstance to direct attacks against civilians; indeed, as noted, to do so intentionally amounts to a war crime. 
 
It is also generally forbidden to direct attacks against what are called “civilian objects,” such as homes and apartments, places of worship, hospitals, schools, or cultural monuments, unless they are being used for military purposes. Military objects that are legitimately subject to attack are those that make an “effective” contribution to military action and whose destruction, capture or neutralization offers a “definite military advantage.” Where there is doubt about the nature of an object, it must be presumed to be civilian. 
 
The mere fact that an object has civilian uses does not necessarily render it immune from attack. It, too, can be targeted if it makes an “effective” contribution to the enemy’s military activities and its destruction, capture or neutralization offers a “definite military advantage” to the attacking side. However, such “dual use” objects might also be protected by the principle of proportionality, described below. 
 
Even when a target is serving a military purpose, precautions must always be taken to protect civilians. 
 
Is Hezbollah’s firing of rockets into Israel lawful under international humanitarian law? 
 
As a party to the armed conflict, Hezbollah has a legal duty to protect the life, health and safety of civilians and other non-combatants. The targeting of military installations and other military objectives is permitted but Hezbollah must take all feasible precautions to avoid civilian harm and is prohibited from targeting civilians, launching indiscriminate attacks, or attacking military objects if the anticipated harm to civilians and other noncombatants will be disproportionate to the expected military advantage. Hezbollah’s commanders must choose the means of attack that can be directed at military targets and will minimize incidental harm to civilians. If the weapons used are so inaccurate that they cannot be directed at military targets without imposing a substantial risk of civilian harm, then they should not be deployed. Deliberately attacking civilians is in all circumstances prohibited and a war crime. 
 
While Human Rights Watch has not yet conducted a field examination to determine whether any of these attacks aimed to target a military object, preliminary information suggests that rockets fired by Hezbollah may be so inaccurate as to be incapable of being targeted, but are rather used to target a generalized area. As Human Rights Watch said in a 1997 report on Lebanon and Israel, “Katyushas are inaccurate weapons with an indiscriminate effect when fired into areas where civilians are concentrated. The use of such weapons in this manner is a blatant violation of international humanitarian law.” That is, their use in civilian areas violates the prohibition on indiscriminate attacks and would be a war crime. Customary international law prohibits such bombardment near or in any area containing a concentration of civilians, even if there are believed to be military objectives in the area.