Hamas planned the devastating terror attack on Israel for two years while pretending to be governing Gaza — but was “surprised” at being able to kidnap and slaughter so many, according to an exiled leader.

Ali Barakeh, a member of the terror group’s exiled leadership in Lebanon, said key members intentionally projected a “rational” image to the world to hide its sinister intentions.

“We made them think that Hamas was busy with governing Gaza, and that it wanted to focus on the 2.5 million Palestinians [in Gaza], and has abandoned the resistance altogether,” Barakeh told Russia Today TV.

“All the while, under the table, Hamas was preparing for this big attack.”

To help keep it from Israeli intelligence, only “a limited number of Hamas leaders knew it” was coming, Barakeh told the pro-Kremlin channel.

“The zero hour was kept completely secret,” he said.

“The number of people who knew about the attack and its timing could be counted on one hand.”

Still, he and his fellow Hamas leaders never expected to be able to kill more than 1,200 people — mostly civilians, including kids — and kidnap at least 150 others who are now being threatened with execution.

“We were surprised by this great collapse,” Barakeh separately told the Associated Press.

“We were planning to make some gains and take prisoners to exchange them. This army was a paper tiger.”

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In fact, an anonymous diplomatic source told the Middle Eastern news outlet Al-Monitor that the plan had been dramatically more modest.

“They hoped to kill some Israelis, embarrass the IDF [Israel Defense Forces] and return to Gaza with two or three kidnapped Israelis,” the source said.

In fact, an anonymous diplomatic source told the Middle Eastern news outlet Al-Monitor that the plan had been dramatically more modest.

“Instead, they roamed inside Israel for more than a day, killing over a thousand Israelis and getting stuck with something like 200 abductees,” the source added.

“Their success surprised them, too.”

Rather than celebrating the fact, Hamas is now “very worried” that the attack was too successful for its own good, the diplomatic source suggested.

2005: Israel unilaterally withdraws from the Gaza Strip over three decades after winning the territory from Egypt in the Six-Day War.

2006: Terrorist group Hamas wins a Palestinian legislative election.

2007: Hamas seizes control of Gaza in a civil war.

2008: Israel launches military offensive against Gaza after Palestinian terrorists fired rockets into the town of Sderot.