Many people think that the Hashimite pride, which always resulted from honorable attitudes, was more appropriate for the attitude of al Husayn, peace be on him, than the attitude of al-Hasan, peace be on him.
This is a primary viewpoint that suffers from the paucity of an innermost analysis and accuracy.
Al-Hasan was a Hashimite with high glory during all his attitudes. He was similar to his father and his brother in glory. Thus they were all an example to the original reformers in history. However, each one of them had a special jihad (armed struggle), message, and attitudes which he derived from the core of the conditions that surrounded him.
These conditions were early examples of jihad, glory, supporting the usurped right to authority.
Al-Husayn faced death through killing during his condition, and al-Hasan retained his life through making peace (with Mu'awiya) during his condition. With these two ways they were able to continue their doctrine and to condemn their enemies. In the meantime these two ways were the necessary logical solutions for the problems of both conditions.
These solutions were the best means, which al-Hasan and al-Husayn followed to please Allah, the Most High, not to win the life in this world. They (i.e., the solutions) are the real victory that last throughout history though al-Hasan and al-Husayn were apparently deprived of their rights and their succession to authority.
The two sacrifices (i.e., al-Husayn's sacrifice in his life, and al Hasan's sacrifice in his succession) are the utmost degrees to which the original leaders aspire during their human revolutionary attitudes.
The time factors accompanied both al-Hasan and al-Husayn during their succession. They created for each of them a private condition towards his supporters, and a private condition towards his enemy. In other words the two brothers had two different conditions. As their conditions were different, their ways of jihad were different. Therefore their ends were different.
The following are the conditions their supporters and their enemies caused:
1. The Conditions their Supporters caused
For al-Husayn, peace be on him, he suffered from the treason of his Kufan companions. Such a kind of treason helped al-Husayn take a step to pave the way for his glorious success in history. That is because the people had broken their pledge of allegiance to al-Husayn before he declared war mobilization.
Thus his little army was empty of any traitorous person on the day when he stood to fight against his enemies to achieve his ideal objectives.
However, the treason from which al-Hasan, peace be on him, suffered at the Camp of Maskan and the Camp of al-Mada'in was quite different from that which al-Husayn suffered. That is because al-Hasan declared war mobilization, and then his army moved to the mentioned camps. However, the enemy rumors played an important role in scattering the army. Thus chaos, plots, and treason spread all over it. Accordingly, al-Hasan was unable to wage holy war (jihad) against his enemies. In other words this was the army through which al-Hasan lost hope of winning victory in that war.
From here we understand that Al-Hasan's supporters pledged allegiance to him, and accompanied him to his camps as holy fighters (mujahidin). However, they broke their allegiance to al-Hasan, disobeyed him, and joined his enemies. Thus they were worse than those who had broken their allegiance to al-Husayn before he met his enemies.
In this manner al-Husayn paved the way to fight against his enemies when the events of treason before the battle helped him form the most wonderful army in history in loyalty and obedience though his army was few in number.
As for al-Hasan, he was unable to retain supporters even from his sincere Shi'ites. For he was not sure that he would gather them and direct their movements because of the chaos which his enemies spread.
Therefore, isn't there a great difference between their two conditions towards their supporters?
2. The Conditions their Enemies caused
The enemy of al-Hasan was Mu'awiya, and the enemy of al Husayn was Yazid b. Mu'awiya. History is full of differences between Mu'awiya and Yazid. For example, the son (i.e., Yazid) had plain dullness, while the father (i.e., Mu'awiya) had a deep viewpoint that the people regard as smartness.
The enmity of these two men (i.e., Mu'awiya and Yazid) towards al-Hasan and al-Husayn did not result from an accidental condition. Rather it was a past historical enmity between banu Hashim and banu Umayya.
The Umayyads did not match the Hashimites one day. Rather the Umayyads showed enmity towards the Hashimites, for the former feared that the latter would take their authority. This is the reason why the people and the historians mention the Umayyads face to face with the Hashimites.
Now we have the right to ask: Isn't there a great difference between those who follow desires and those who follow ideals? Isn't there a clear difference between those who had corrupt lineages and those whom Allah purified completely as it is in the Qur'an? Isn't there an obvious difference between the corrupt people and those who adopted intellectual talents, good manners, pure race, and sciences that have played an important role in developing man in all cultural fields? Such were the Hashimites who brought light to the world. 
How different they are!
What al-Hasan b. 'Ali anticipated was likely. For if he had waged a hopeless war against his historical enemy Mu'awiya b. Abu Sufyan b. Harb, the war would have led to the greatest disaster against Islam. Also it would have destroyed all Shi'ites of the members of the House (Ahl al-Bayt), peace be on them. In this connection Mu'awiya had excellent abilities to carry out this plan to end that long historical enmity towards 'Ali, his sons, and their Shi'ites.
We have already mentioned this subject. Thus there is no need to mention it again.
However, such a possibility was enough for al-Husayn when the young man (i.e., Yazid) antagonized him. That is because Yazid was luxurious. He was unable to solve problems nor was he able to mobilize the trends nor was he able to make plans: Moreover, his ambition was to be a king with many treasuries, even though he faced al-Akhtal the poet whose words al-Bayhaqi has narrated:
"Your religion, indeed, is like the religion of the donkey
Rather you are more unbelieving (person) than Hurmuz."
This possibility was sufficient for al-Husayn when the sword of terrorism (i.e., Yazid) began to chase the Shi'ites everywhere, made them homeless and imprisoned those great figures who followed the doctrines of the members of the House (Ahl al-Bayt), and to whom these doctrines were entrusted to convey them to the generations after them.
Thus al-Husayn thought that it was better for him to go on carrying out his decision. He was sure of his plan, his objectives, and their future towards his enemies.
As for al-Hasan, he was not as sure as his brother al-Husayn. That is because al-Hasan suffered from the spiritual backgrounds of his army. Moreover, among his enemies were Mu'awiya and his fearful servants who made spiteful hostile plans.
Finally, al-Husayn made use of Mu'awiya's mistakes such as his attacks against the peaceful Muslim cities, his attitude towards the conditions of the Peace Treaty of al-Hasan, his killing al-Hasan with poison, his pledge of allegiance to his son Yazid, and so on. All these errors of Mu'awiya, in addition to the support of the Muslim public opinion urged al-Husayn to take steps against the Umayyads.
In the meantime al-Husayn made us of the errors of Yazid, Mu'awiya's successor, who was fond of monkeys and wine. All these things were appropriate factors for al-Husayn to carry out his plan.
Al-Husayn's conditions towards his enemies, and his conditions towards his supporters agreed with each other on supporting his movement, carrying out his task, and leading him to the glorious victory through which he succeeded with Allah and in history.
As for al-Hasan, as we have already mentioned, he was tired of the conditions which his companions caused. Thus these conditions prevented him from obtaining martyrdom. Also he suffered from the conditions which his enemies caused. So these conditions prevented him from waging war against them though he was aware that such a kind of war would destroy his doctrines.
For this reason al-Hasan thought that it was necessary for him to develop his way of jihad, and to start his battle through making peace with Mu'awiya.
The objectives which al-Hasan wanted to accomplish through his Peace Treaty with Mu'awiya forced Mu'awiya and his party to face a quick failure in history.
Indeed, after this study, it is difficult for us to distinguish which of the two brothers (i.e., al-Hasan and al-Husayn), peace be on them, had a greater effect in his jihad, more intense influence on his objectives, and a more careful opinion in defeating his enemies.
It is obvious that the Umayyads faced many hardships after the Peace Treaty. That was because of al-Hasan's plans and his directions. Indeed all these hardships took place due to this successful plan which al-Hasan's enemies supported, whether they knew that or not.
 In reply to Mu'awiya, the Commander of the faithful said: "Inspite of our old established honor and our well- known superiority over your people, we did not keep away mixing with you and married and got married (among you) like equals although you were not so. How could you be so when (the position is that) from us is the Prophet while from you is the liar, from us the Lion of Allah while from you is the Lion of the allies, from us is the two Lords of the youth of Heaven while from you are the children of the fire, from us is the mistress of the women of the worlds while from you is the bearer of firewood, and there are many distinctions between you and us."