Attacking Pakistan but not by name, Indian Army chief General Bipin Rawat on Tuesday said "our western neighbour" was ceaselessly supporting terrorists and warned that India will achieve "decisive success" if war is forced.
"If our nation is forced into a situation of war, decisive success will be ours," he said addressing the 71st Army Day parade.
Warning that security challenges will be more complex in future, the Army chief said: "There is a need to enhance our professional skills to deal with any danger."
Gen Rawat said that a new policy had been adopted on the border with China and the armies of the two countries told to maintain peace.
Referring to action taken in the wake of unending firing by Pakistani troops, he said: "We have been giving a befitting reply to the enemies on the Line of Control (LoC) that has led to heavy loss of lives and logistics."
Accusing Pakistan of helping terrorists, Gen Rawat said: "I warn the enemy that we will not hesitate to take heavy action in reply to what they are doing against our country.
"Not only is our neighbouring country supporting terrorism but it is also providing arms and facilitating training to terrorists. That country (Pakistan) has been included in the category of countries sponsoring terrorism."
He said the Army's anti-infiltration operations were on and would continue.
On terrorism in Jammu and Kashmir, the Army chief said his men had caused heavy losses to the militants with the help of other security agencies.
Asserting that the Army was determined to crush terrorism, Gen Rawat said terrorists in Jammu and Kashmir were in a "hopeless" situation.
"The result is that the terrorists are now threatening teenagers to take to arms in Jammu and Kashmir. We don't want that terrorists continuously keep threatening citizens."
He said the situation in the northeastern states was "under control" and that focused intelligence-based operations by Army and Assam Rifles were on.
The Army was also training paramilitary forces and police in Maoist affected areas.
Gen Rawat also talked about "revolution in military affairs" to make the war strategy modern.
To deal with future challenges, he said the 1.9 million strong Indian Army had adopted the techniques of "collective" changes in weaponry and its "reorganisation" was on.
"The aim of our capacity is being increased in a rapid way. Army's modernization is being done. We have been successful in procuring new weapons and in the technique to work in darkness."
Gen Rawat said the Army had added projects like K-9 Vajra gun, Prahaar missile system, mine protected vehicles and Aakash missile system.
The Army chief also advised soldiers and their families to use social media very carefully.
The Army Day is celebrated to commemorate the day when Field Marshal M. Cariappa took over as Commander-in-Chief of the Indian Army from General Sir Francis Butcher on January 15, 1949.