The missile-defense drill had been trumpeted as showing US commitment to Israel's security. Some Israeli officials criticize President Obama for excessive caution in an election year.
Iran has many capable engineers, and none of the victims appear to have had indispensable knowledge. But spreading fear among the living can slow them down and deter young recruits.
Israel's former spy chief has warned against a preemptive strike on Iran's nuclear program, as has the US, citing its potential to boost Iran's regime at home and endanger US troops in the Middle East.
A swap today of alleged Israeli spy Ilan Grapel for 25 Egyptian prisoners helps patch up relations between Israel and Egypt.