<quote> The alliance also increased the pressure on the Milosevic Government by stepping up strikes on electrical transmission systems and radio relay towers in the heart of Serbia. In doing so, it demonstrated that it would not be deterred by the public outcry over civilian casualties caused by a relative handful of mistaken attacks and errant bombs.
And by holding down its own losses to the surprisingly low toll of two combat planes over more than 33,000 missions, it also proved that it could carry out its strikes at a negligible cost to itself. </quote>
[and]
<quote> Analysts of American public opinion have found, after examining polls dating from the Korean War, that the single most important factor that can turn the American public against a foreign war is a spike in U.S. combat casualties.
"The public applies a fairly reasonable cost-benefit analysis when evaluating foreign affairs, but it vastly overvalues the lives of Americans and undervalues the lives of foreigners," said John Mueller, an expert on polling and foreign wars who is a professor of political science at the University of Rochester. Polling since April by the Pew Research Center has found 60 percent of Americans "very worried" about American combat casualties, although there have been none. The polling also found that even after bombing mistakes killed scores upon scores of civilians, just 40 percent of Americans were "very worried" about that.
By that measure, the Kosovo effort was perfectly attuned to American opinion. The sole American deaths occurred when two helicopter pilots died in a training accident. </quote>