Even thousands is a massive loss.
If we're to take independent analysis and claims from Iran and Hezbullah seriously, then Hezbullah has anywhere between 500,000 to 1,000,000 rockets. Thousands of losses is a huge dent. You also are losing people who have been trained to use those rockets effectively.
Unless Hezbullah responds in force, Israel will just keep destroying Hezbullah's arsenal without facing any real threat.
Of course Hezbullah would risk an Israeli invasion, but it's high time for them to realize that it was going to happen anyway, so they may as well choose the terms of engagement themselves, instead of letting Israel dictate the circumstances.
