No. Because from a relative perspective, saying 'nobody is suffering' is different from knowing it, just as saying 'Kailash', 'Kailash' a hundred times does not make it equal to visiting Kailash.
By Advaita Perspective
Nobody is really suffering.
Brahma satyam jagat mithya (Reference: Vivekachudamani)
Brahman is the only truth, the world is unreal.
Because the true identity of each person is the soul, not the body. The soul can never be subject to suffering.
Sri Krishna says in Gita 2:16, 18
In the unreal there is no duration and in the real there is no cessation; indeed the conclusion between both the two has been analyzed by knowers of the truth.
But know that by whom this entire body is prevaded (Atma), is indestructible. No one is able to cause the destruction of the imperishable soul.
Then can I harm anyone?
You can harm no-one because their atma is just as eternal as yours. How can you harm the atma? The Atma is invinvible and cannot be harmed.
Sri Krishna says in Gita 2: 19, 21
Anyone who thinks the soul is the slayer and anyone who thinks the soul is slain both of them are in ignorance; the soul never slays nor is slain.
O Arjuna, one who knows the soul as eternal, unborn, undeteriorating and indestructable; how does that person cause death to anyone and whom does he slay?
Then who is suffering?
It is the body that suffers.
The material body of the indestructible, immeasurable and eternal living entity is sure to come to an end; therefore, fight, O descendant of Bharata.
O son of Kuntī, the nonpermanent appearance of happiness and distress, and their disappearance in due course, are like the appearance and disappearance of winter and summer seasons. They arise from sense perception, O scion of Bharata, and one must learn to tolerate them without being disturbed.
If we are not really suffering then why do we feel that we are suffering?
It is because of wrong association. Avidhya. We think we are the body, thus we suffer.
Swami Adiswarananda describes this:
Patanjali (the teacher of the Yoga system), in one of his aphorisms, describes the causes of suffering as five: ignorance, ego-sense, attachment, aversion, and clinging to life.
So in other words, all suffering is due to the attachment to our false identity. Our true identity is Atma. But we think we are the body (there are actually several layers of bodies, called three upadhis and five sheaths).
But I know now that I am not the body, then why do I feel that I am suffering?
Reading something does not mean that you have realized it. You have now read that you are not the body. But still you have not realized it. In other words, your knowledge is merely a theoretical knowledge and not a practical knowledge. Here is an example to understand. Suppose your friend reads a hundred books about how to drive a car. Will you then give him your car and say 'drive me to Kodaikannal'? Generally, the answer is No. Why? because even though He has read it, still He needs practice isn't it? His theoretical knowledge is not good enough. Practical knowledge is necessary.
Similarly you have read that you are not the body. But now it is time to realize it. Practical knowledge is necessary to remove suffering.
Also remember that the law of karma is not cessated until practical realization dawns. Merely knowing intellectually (without practical) that 'I am not the body' and then harming others, will bring about similar harm back to the jiva.
Swami Vishwananda says in the comment that:
I would only add that it is correct that you cannot 'ultimately' harm anyone. But so long as you see the world as real, then if you do harm, you will suffer the karma. To have the intellectual understanding that no one suffers and to cause suffering is tamasic. One should have the practical understanding that to cause suffering to another is actually causing suffering to your own self.
Then how to practice and end this suffering?
By realizing who we really are which is the indestructible atma.
How to realize this?
By Bhakti Yoga, Jnana Yoga or Karma Yoga
Bhakti Yoga - By practising love for God and service to all because God resides in all. (Reference 'Bhakti Yoga' by Sri Swami Sivananda)
Jnana Yoga - By investigating into the Truth about our true identity and by practising the feeling of detachment and renunciation.
Karma Yoga - By helping all, without any desire for fruits. [Reference: Gita 2:47]
Which of these paths have the words 'harm others'? None of these. In other words, in order to practically realize who we really are, a certain amount of discipline, goodness and virtues are helpful.
Can we harm other people in Bhakti?
Sri Swami Sivananda describes that good conduct is absolutely necessary:
Good conduct which is in accordance with perfect moral law is an auxiliary to pure Bhakti and it follows the true Bhakta wherever he goes. One cannot develop true devotion to God if he is crooked in his heart, if he has got objects of love in this world, if he is tempted by charming worldly thing... Perfect detachment from all objects is a preliminary to real devotion. Vairagya is the product of real love for God. One who has love for the world cannot have love for God. Where there is Kama, there cannot be Rama and where there is Rama there cannot be Kama. Love for the world and love for God are diametrically opposite things.
How about other paths?
Swami Vivekananda, describes the importance of service and doing good (not causing harm):
My children, the secret of religion is not in theories but in practice. To be good and to do good---that is the whole of religion.
If you harm the body of others, then you can not realize the truth that you are that Atma.
The answer lies here, - intention. Why do you harm others? To gain money? Then you are attached to money. To gain victory? Then you are proud. So long as you have:
you cannot realize the Truth. [Arishadvargas ]
These six enemies of Man, blind us and make us believe that we are the 'body'. Then we get feeling that we can harm other bodies. But in truth we are the eternal Atma. We cannot be harmed, and we cannot harm others.
Sri Krishna asked Arjuna to fight Mahabharata war. Again the reason is intention. Arjuna was not motivated by His own selfishness at that time. But rather He was fighting to rid the world of adharma. To show to the world that Dharma always wins! Therefore intention matters. All the best.
So from an Absolute standpoint, you cannot harm others, because they too are the immortal Atma, just as you are.
From a relative standpoint, you cannot harm others, because your attachment to the body grows because of that. Then you can not be free of your ignorance.
All the best!!