Bharatiya Janata Party (BJP) President Amit Shah on Saturday took charge as the 30th Union Home Minister at a time when the country is facing terrorism, secessionism and Maoist insurgency challenges.The 55-year-old BJP leader assumed charge a day after he was assigned the crucial Home portfolio, succeeding Rajnath Singh, as Prime Minister Narendra Modi's government returned for a second term. The leadership change in the high-profile ministry is expected to usher in a certain decisiveness and an iron-handed approach to terror, insurgency and secessionism.However, former Home Minister Rajnath Singh had given a free hand to security forces in Jammu and Kashmir, leading to heavy casualties among terrorists, Shah is expected to be more proactive and lead from the front.He was welcomed by Union Home Secretary Rajiv Gauba and IB chief Rajiv Jain soon after he reached his North Block office