Dagan was conscripted into the Israel Defense Forces (IDF) in 1963.
He was considered for the elite Sayeret Matkal unit, but ended up joining the Paratroopers Brigade.
He completed his compulsory service in 1966, but was called up as a reservist in 1967, and fought in the Six-Day War as an officer, commanding a paratrooper platoon on the Sinai front.
In the early 1970s, he commanded an ad hoc undercover commando unit, known as Sayeret Rimon, whose task was to combat the increasing violence in the Palestinian territories.
In 1971, he received a Medal of Courage for tackling a wanted terrorist who was holding a live grenade.
Dagan later fought in the 1973 Yom Kippur War as an officer on the Sinai front, and participated in the crossing of the Suez Canal.
During the 1982 Lebanon War, he commanded the Barak Armored Brigade, and was one of the first brigade commanders to enter Beirut.
In the 1990s, he held a series of high-level positions in the IDF command, eventually reaching the rank of Major General before retiring from the army in 1995, after 32 years of service.

Dagan later served as a counterterrorism adviser to Prime Minister Benjamin Netanyahu, and he initially served as a National Security Adviser to Prime Minister Ariel Sharon.
Sharon appointed him Director-General of Mossad in August 2002, replacing outgoing Director Efraim Halevy.
As Mossad director, Dagan was responsible for intelligence, counter-intelligence, and counter-terrorism activities outside of Israel and the Palestinian Territories (which are under the jurisdiction of Shabak as they are considered domestic areas).
He was allegedly aggressive in ordering killings of terrorists on foreign soil.
According to Mossad veteran Gad Shimron, "Israel is in the paradoxical situation of not having a death penalty but allowing itself to target Arab terrorists outside its borders with almost complete impunity.
Meir Dagan fully subscribes to this thinking, unlike some of his predecessors".
By November 2004, at least four foreign terrorists had already been killed in suspected Mossad operations, and three major terrorist attacks planned against Israeli civilians abroad had been foiled.

Ehud Yatom, a member of the Knesset Subcommittee on Secret Services, stated that "as someone who is privy to the facts but not at liberty to divulge them, I can say this with complete authority.
The Mossad under Meir Dagan has undergone a revolution in terms of organization, intelligence and operations."
Under Dagan's watch, Mossad tripled its recruitment efforts, launching a website where people can apply to join.
Reportedly, much of its annual budget of $350 million was diverted from traditional intelligence gathering and analysis to field operations and "special tasks".

Dagan was reconfirmed as Mossad director until the end of 2008 by Prime Minister Ehud Olmert in February 2007, and in June 2008, Olmert again extended his tenure until the end of 2009.

In mid-2007, Dagan had a "spat" with the Deputy Director N, who was thought to be a candidate for replacing Dagan in late 2008.
Dagan restored his former deputy T to the post and Dagan was thought likely to recommend T as his replacement.

He was re-appointed in 2009 by Prime Minister Benjamin Netanyahu to serve until the end of 2010.
 In June 2010, a report from Channel 2 stated that Netanyahu had denied a request by Dagan for another year as Mossad director, though this was quickly denied by the Prime Minister's Office.
In November 2010, Tamir Pardo was announced as his replacement.

Following his departure, Dagan made several controversial public statements concerning the prudence of an Israeli military attack on Iran's nuclear facilities, openly contradicting the positions of Prime Minister Netanyahu.
He called it a "stupid idea" in a May 2011 conference.
After Dagan voiced criticism of the prime minister, he was asked to return his diplomatic passport before its expiry date.
 Dagan repeated the opinion in a March 2012 interview with Lesley Stahl of CBS News' 60 Minutes, calling an Israeli attack on Iran before other options were exha
Dagan was conscripted into the Israel Defense Forces (IDF) in 1963. He was considered for the elite Sayeret Matkal unit, but ended up joining the Paratroopers Brigade. He completed his compulsory service in 1966, but was called up as a reservist in 1967, and fought in the Six-Day War as an officer, commanding a paratrooper platoon on the Sinai front. In the early 1970s, he commanded an ad hoc undercover commando unit, known as Sayeret Rimon, whose task was to combat the increasing violence in the Palestinian territories. In 1971, he received a Medal of Courage for tackling a wanted terrorist who was holding a live grenade. Dagan later fought in the 1973 Yom Kippur War as an officer on the Sinai front, and participated in the crossing of the Suez Canal. During the 1982 Lebanon War, he commanded the Barak Armored Brigade, and was one of the first brigade commanders to enter Beirut. In the 1990s, he held a series of high-level positions in the IDF command, eventually reaching the rank of Major General before retiring from the army in 1995, after 32 years of service.
Dagan later served as a counterterrorism adviser to Prime Minister Benjamin Netanyahu, and he initially served as a National Security Adviser to Prime Minister Ariel Sharon. Sharon appointed him Director-General of Mossad in August 2002, replacing outgoing Director Efraim Halevy. As Mossad director, Dagan was responsible for intelligence, counter-intelligence, and counter-terrorism activities outside of Israel and the Palestinian Territories (which are under the jurisdiction of Shabak as they are considered domestic areas). He was allegedly aggressive in ordering killings of terrorists on foreign soil. According to Mossad veteran Gad Shimron, "Israel is in the paradoxical situation of not having a death penalty but allowing itself to target Arab terrorists outside its borders with almost complete impunity. Meir Dagan fully subscribes to this thinking, unlike some of his predecessors". By November 2004, at least four foreign terrorists had already been killed in suspected Mossad operations, and three major terrorist attacks planned against Israeli civilians abroad had been foiled.
Ehud Yatom, a member of the Knesset Subcommittee on Secret Services, stated that "as someone who is privy to the facts but not at liberty to divulge them, I can say this with complete authority. The Mossad under Meir Dagan has undergone a revolution in terms of organization, intelligence and operations." Under Dagan's watch, Mossad tripled its recruitment efforts, launching a website where people can apply to join. Reportedly, much of its annual budget of $350 million was diverted from traditional intelligence gathering and analysis to field operations and "special tasks".
Dagan was reconfirmed as Mossad director until the end of 2008 by Prime Minister Ehud Olmert in February 2007, and in June 2008, Olmert again extended his tenure until the end of 2009.
In mid-2007, Dagan had a "spat" with the Deputy Director N, who was thought to be a candidate for replacing Dagan in late 2008. Dagan restored his former deputy T to the post and Dagan was thought likely to recommend T as his replacement.
He was re-appointed in 2009 by Prime Minister Benjamin Netanyahu to serve until the end of 2010.  In June 2010, a report from Channel 2 stated that Netanyahu had denied a request by Dagan for another year as Mossad director, though this was quickly denied by the Prime Minister's Office. In November 2010, Tamir Pardo was announced as his replacement.
Following his departure, Dagan made several controversial public statements concerning the prudence of an Israeli military attack on Iran's nuclear facilities, openly contradicting the positions of Prime Minister Netanyahu. He called it a "stupid idea" in a May 2011 conference. After Dagan voiced criticism of the prime minister, he was asked to return his diplomatic passport before its expiry date.  Dagan repeated the opinion in a March 2012 interview with Lesley Stahl of CBS News' 60 Minutes, calling an Israeli attack on Iran before other options were exha
Meir Dagan