A major task of the next prime minister will be the appointment of the heads of the Shin Bet (Israel Security Agency), the Mossad and, likely, also the IDF.Shin Bet director Nadav Argaman’s five-year term concludes in May, meaning that there is a strong likelihood that his term will end before a new government is formed.If that occurs, it is unclear whether Argaman will retire as scheduled. Netanyahu’s first preference is to appoint National Security Council chief Meir Ben-Shabbat, a former top Shin Bet official, as Argaman’s successor.But if Netanyahu is still merely a transitional prime minister and has not yet formed a government, Attorney-General Avichai Mandelblit may block such an appointment.While Ben-Shabbat has some support within the Shin Bet because of his past service there - serving as a division head in three different capacities - there are also many in the agency who have threatened to resign if he is appointed.For them, he is seen as too close to Netanyahu and too and compliant with his requests, and there are concerns that he would promote the Likud leader's political agenda over professional considerations. In addition, Blue and White’s Benny Gantz, even with reduced political support, technically has vetoes over top appointees, including the head of the Shin Bet.It is unclear if he would agree to Ben-Shabbat’s appointment.There is bad blood between the two from when the NSC chief went behind Gantz to get information from top IDF officials relating to a possible US sale of F-35 fighter jets to the United Arab Emirates.If Netanyahu cannot appoint Ben-Shabbat, there might be immediate contention over who would be acting Shin Bet director – or Argaman’s term might be extended.Argaman is highly respected for reducing terrorism and for major upgrades in the cyber realm. But he publicly clashed over Netanyahu’s plans last summer to annex portions of the West Bank as well as compelling the agency to track coronavirus-infected citizens.The prime minister has consistently wanted to involve the Shin Bet in the fight against the coronavirus.Argaman has said it is a distraction from the main mission of counterterrorism, and that drawing public attention to Shin Bet methods has possibly exposed aspects of counterterrorism technology.So if it is Netanyahu’s call, he might prefer a more compliant acting Shin Bet chief, even if he cannot put Ben-Shabbat into the director’s chair. Mossad chief Yossi Cohen must be replaced in June. Cohen’s term was extended before the election from January to June, and Netanyahu has already said he wants D., the current deputy Mossad chief, to succeed Cohen.But Mandelblit has blocked D.’s appointment, because Netanyahu is a transitional prime minister.There is, however, a greater likelihood of a new government by June than by May.But what if coalition negotiations continue, or if they fail and a fifth election is called?Cohen has made clear he will not extend his term again. He wants the three-year cooling off period to start so that he can eventually enter politics. Netanyahu has in the past said that he sees Cohen as his potential successor.In this case, D. or some other figure might be appointed temporary Mossad chief.Gantz might try to intervene, especially considering that Netanyahu violated a coalition agreement to consult the defense minister when announcing D. was his choice to lead the intelligence agency without previously checking with Blue and White.If Netanyahu does not get to pick the next Shin Bet chief, sources expect Argaman to support his current deputy R., whom he has tried to position as his successor and with whom he worked in a variety of levels in operations over the years.A third candidate is also known as R. and was a former deputy chief of the Shin Bet.In comparing the two Rs, some sources said that the prior deputy chief R. has a broader worldview when it comes to technology, data collection and analysis of intelligence issues.Some also point out that prior R. has more experience in large-scale military operations from his service during the Gaza war of 2014, something the current R. has not quite had to match.Further, some say that prior R. is more beloved, inspires more social cohesion among the rank and file than current R. and could be a compromise candidate acceptable to Netanyahu and the current Shin Bet leadership.But prior R. may have burned some bridges. Previously, he told Channel 12’s Uvda program, following the 2014 Gaza war, that the agency had warned the IDF and Netanyahu that Hamas was preparing for conflict, but was ignored.This won him enemies, some of whom hold him responsible for failing to sound the alarm loudly enough, and it may have hurt him with Netanyahu.Also, some say that current R. may be more charismatic and more of a stand-out talent in operations than prior R., and has gained experience with Shin Bet branches beyond the operations side by serving consecutively in the agency’s No. 2 and No. 3 roles.If someone other than Netanyahu picks the next Mossad chief, then A., a former deputy chief, may be back in the running after losing narrowly to D. in Netanyahu’s eyes.A. also may have won some positive attention from anti-Netanyahu forces after blasting him on Iran strategy (while agreeing with him on some tactics), in a recent interview with Yediot Aharonot.Further down the line is the scheduled replacement of IDF Chief of Staff Lt.-Gen. Aviv Kohavi, who is in place at least until January 2022, and could have his term extended for a year until 2023.If Netanyahu remains prime minister, he may be more likely to switch Kohavi in January 2022.This would add to his legacy, since there may be a verdict from his criminal trial before January 2023, which could force Netanyahu from office before Kohavi’s extended term ends.In contrast, if someone other than Netanyahu becomes prime minister, Kohavi’s term will likely be extended until January 2023. This is because it is almost routine to extend the term of highly respected chiefs of staff, like himself.Finally, everything comes back to Cohen.Ben-Shabbat, in the short term, has beaten out Cohen for future control of Iran policy, partially because Cohen is about to retire.However, if Netanyahu gets to move Ben-Shabbat to the Shin Bet, this could reopen Cohen’s access to Iran policy, even as an informal envoy.