When בלק asked בלעם to curse the Bnei Yisrael,
he said ארה *לי, "curse me*".
Mori V'Rabi Harav Hagaon R.Shlomo.Miller Shlita said,
In Parshas לך לך, Hashem said," ואברכה מברכיך
ומקללך אאר I will bless those who bless you and
those who curse you I will curse".
בלק was aware of this, yet he still insisted on having the
Bnei Yisrael cursed. even though as a result of this,
בלק himself will be cursed.
The שונאי ישראל attempt to harm the Yidden even when
they know they are harming themselves & will lose out
by doing so.
At the end of the war, the Nazis ימ"ש, instead of using
their trains for their war effort to save their own military,
they used the trains to transport the Hungarian
Jews to Auschwitz.
Even though בלעם blessed the Bnei Yisroel, he wasn't
entitled to be blessed because it wasn't him who blessed
the Bnei Yisroel
It was Hashem's Brocho coming out from Bilam's mouth.
*see אור החיים