Good Question. This answer is gonna be very long, so bear with me. But here, we need to know the reasons correctly as to why these incidents happened.
WHY WAS LORD SHIVA NOT ABLE TO SAVE SATIDEVI?
As per the Bhagavata Purana, Lord Brahma came from Lord Vishnu’s navel. Lord Brahma gave birth to mind-born sons known as the Brahma Maanasa Putras. He even gave birth to Daksha, named Devata. This Daksha was married to Prasooti, the daughter of Svaayambhuva Manu. Now, Daksha and Prasooti had 14 daughters, of whom 13 were married to Sage Kashyapa, and the 14th one was married to Lord Shiva. This wife of Lord Shiva was known as Satidevi.
Now, once Daksha Prajapati arranged a yagya. He invited everyone, along with Lord Brahma, Lord Shiva, etc. Lord Vishnu wasn’t present at that yagya. Now, what happened was that Daksha Prajapati came there, and everyone stood up to respect him. But then, Daksha saw Lord Shiva, who was sitting along with Lord Brahma, His father. Now, Lord Shiva was meditating on Lord Vaasudeva present within Him. Though Lord Shiva is far superior to Daksha Prajapati, since Daksha is the father-in-law of Lord Shiva, He bowed to Daksha in His mind only and didn’t show it externally.
Daksha didn’t know this and thought Lord Shiva was disrespecting him. Enraged by this, He cursed Lord Shiva that there wouldn’t be any oblation in the name of Lord Shiva in the yagya. At this, Nandishwara was very angry and cursed Daksha that he would not know the deeper spiritual meaning of the Vedas. At this, Sage Bhrigu too cursed Nandishwara and the Shiva ganas that they would become paashandas. Lord Shiva noticed this exchange of curses, and then left that place. Nandishwara and others also left that place along with Lord Shiva.
Now, Daksha again organized a yagya after some time. He invited everyone, but didn’t invite Lord Shiva and Satidevi. Satidevi came out and saw that everyone was going in the vimaana. Some asked Satidevi, “O Sati! Aren’t you coming for the great sacrifice that your father Daksha has organized?” Satidevi went to Lord Shiva and said, “O Lord! Let’s go and attend Daksha Prajapati’s yagya.”
Lord Shiva refused, saying that when someone hasn’t invited us, we shouldn’t forcibly go there. At this, Satidevi said, “But O Lord! Going to father or guru’s house without invitation is valid! Therefore, we must attend the sacrifice.” But Lord Shiva said, “Sati! I agree with you on this. But now the situation is different!” and Lord Shiva narrated the whole incident of how Daksha cursed Him and how the exchange of curses took place. Lord Shiva even warned Satidevi about the consequences of going to the yagya, but Satidevi didn’t agree and urged him to go there.
Lord Shiva, assuming it to be the will of Lord Srihari, allowed Her to go. He already knew what was about to happen. Lord Shiva didn’t come there, but Satidevi went to the yagya. As She went there, Prasooti, Her mother, Her sisters, and all welcomed and talked to Her. But Daksha Prajapati, didn’t even talk to Her. Satidevi came to know that there was no oblation in the name of Lord Shiva. She felt insulted and said, “O Daksha! What are you thinking of? Do you even know how great Lord Mahadeva is, and what is His position? Just by chanting the two syllables ‘Shi’ and ‘Va’ is enough to burn all our sins. In that case, you dare to insult Lord Shankara?”
But Daksha didn’t pay any heed to Her. Now, She thought, “In case anyone insults a high-personality, then one should do either of these: 1. Cut down the tongue of the person. 2. Refute him, if possible. 3. Leave that place. I cannot cut Daksha’s tongue because he is my father. I cannot also refute him, because he is my father, and I cannot talk against him. If I leave and go back to Kailasa, Lord Shiva will say, ‘O Daakshaayani! You came back!’ I cannot hear the word Daakshaayani from His mouth! I don’t want to be called the daughter of a man who insulted Lord Shiva!” and, thinking so, Satidevi decided to do deha tyaaga.
She summoned the yogic fire, remembered Lord Shiva and Lord Narasimha within Lord Shiva, and burnt Herself in the yogic fire. After this, Her deha was reduced to ashes. This Satidevi was afterwards born as Aparna, the daughter of Himavan raja and Mena devi, and married Lord Shiva again. So, this is why Satidevi did dehatyaaga, and it was destined to happen. After that, when Lord Shiva learnt that Satidevi did dehatyaga, He took out a strand of hair from His jataa and threw it on the ground. From this, Veerabhadra came out. He went to the yagya and destroyed the yagya, removed Sage Bhrigu’s beard, broke Pusha’s teeth for laughing at Lord Shiva, and finally, when He caught Daksha, He couldn’t behead Daksha.
Afterwards, Lord Shiva Himself appeared there and beheaded Daksha, considering it an oblation to Lord Srihari. Then, on the prayers of the devatas, Lord Shiva granted the head of a goat to Daksha and made him alive, and Daksha repented for his mistake. Then Lord Vishnu appeared there, and everyone bowed to Him, and thus the yagya ended.
Plus, Satidevi had tested Lord Rama. When Sita apaharana happened, Lord Rama was weeping a lot. Satidevi saw this and said, “O Lord! You say Rama is your Bhagavan! You chant His name, then why is He, the Parabrahman, crying like this on losing His wife? How can He be Parabrahman? Let me test Him!” At this, Satidevi assumed the form of Sitadevi and went to Rama. She said, “O Lord! Your Sita is here. Why are you crying?” At this, Lord Rama's crying only increased. Rama said, “I am crying because my Ramaa is in Lanka, and here, Satidevi Herself came here to test me!” Realising that Rama was not an ordinary human but Bhagavan Himself, Satidevi bowed to Her. So, since Satidevi did the chintana of the viyoga of Sita-Ramachandra, She had to suffer separation from Lord Shiva.
WHY COULDN’T LORD RAMA SAVE SITADEVI FROM GETTING ABDUCTED BY RAAVANA?
Actually, Lord Rama wanted Ravana to try to kidnap Sita Devi. And Sitadevi was never abducted in real. It was Chhaya Sita who was abducted by Ravana. When Lakshmana refused to go to help Rama, Sitadevi said, “O Lakshmana! You have your evil eye on me? You want to rule Ayodhya? Fine. Go to Ayodhya today itself and stay there only! Here, my husband is in trouble, and you don’t even want to go to help Him?” And then Lakshmana prayed to the vanadevatas and left to help Rama. Now, here, Ravana came in the form of a sage. Sitadevi welcomed him and introduced him to Her, Rama, and Lakshmana.
On hearing this, Ravana revealed his real form. Sitadevi said, “O wicked demon! If my Rama comes and sees you hurting me, He will surely kill you! Nobody can harm my Rama!” But Ravana grabbed Sitadevi by Her hair, and lifted Her by Her legs and took Her to Lanka in the Pushpaka Vimaana. Here, notice the weird behaviour Sitadevi shows. Where was this confidence when She was scolding Lakshmana? Why didn’t She say Rama was unharmed at that time? And why, in front of Ravana, did She say all this about Rama being unharmed by anything or anyone? So, here the Puranas, like the Kurma Purana, clarify that Sitadevi already knew that Ravana would come to abduct Her. So, it was a plan of Sitadevi and Lord Rama. So, according to that plan, Sitadevi acted with Lakshmana as if scolding him, and actually didn’t possess any such intention toward Lakshmana.
Then, when Rama and Lakshmana went away, Sitadevi disappeared. She invoked Agni and asked Her to make an aakruti of Sitadevi, which looked like Her only. And Vedavati entered this Sitaakruti. She was an amsha of Mahalakshmi only. Now, Sitadevi kept some portion (a dx portion of Herself), in that aakruti so that the behavior should match like of Hers, and instructed Indra to enter the aakruti for bodily movements, talking, walking, etc. So, as per that, this aakruti was known as Chhaya Sita, or Sitaakruti. This Sitaakruti was kept in the Parna Kuteera, and it was this Sitaakruti who introduced Herself to Ravana, and Ravana kidnapped Her.
Why did Rama do all this? Could He have simply killed Ravana there itself? No. Because, firstly, Rama had to prove how wicked this Ravana was and wanted to make it world-famous. Second, if He killed Ravana there, it would have been a serious problem. Because, as per the orders of Lord Brahma, the devatas had incarnated as vaanaras to serve Lord Rama. If Rama killed Ravana there itself, then the birth of all these 60 crore vaanaras would have gone to waste. So, that’s why Lord Rama did all this leela. And at last, after killing Raavana, the Agnipravesha was just to exchange this Chhaya Sita with the real Sitadevi, who was in Kailasa, being worshipped by Lord Shiva and Umadevi.
So, this was the reason why Lord Rama let Sita's haran happen.
WHY COULDN’T THE PAANDAVAS PROTECT DRAUPADI’S HONOR?
After the Raajasuya Yagya, Lord Vedavyasa came and said, “O Dharmaraja! After 13 years, a great battle is going to happen. In this battle, all the Kauravas, including Bhishma Pitamaha and all, are going to die. And for all this, you will be the sole reason!” At this, Dharmaraja was very much scared, and thus vowed, “No matter who calls me anywhere, I won’t say ‘no’. No matter who scolds me or insults me, I won’t speak even a word against him/her.”
After this, Duryodhana, Dushasana, Karna, and Shakuni gathered and planned the gambling game to be played in the sabha, and to snatch everything that the Pandavas had. Dhritarashtra invited the Pandavas to this game. Everyone- Bheemasena, Arjuna, Nakula, Sahadevi, Kunti, Draupadi, and all- explained to him not to go. Even Vidura, who was sent by Dhritarashtra to invite Dharmaraja to the gambling, told him not to go. But Dharmaraja had already vowed that he wouldn’t refuse anyone. That’s why he came to play the game of gambling.
Now, Dharmaraja and the other Pandava brothers had come to attend the gambling game. Dharmaraja kept losing his stakes. He kept all his treasury, a divine chariot given by Bahlikaraja, and even his brothers, and then Draupadi, and then himself. But he lost everything, and after that, Dushasana went to Draupadi’s room and dragged Her by Her hair. She was menstruating at that time and was in 1 garment only. Dushasana was teasing Draupadi and was telling Her to leave all Her shyness and go to Duryodhana’s room and climb onto his bed. He also teased Her, “Where is your Krishna? Call Him! Let’s see how your ‘dear Vaasudeva’ helps you?” and brought Her to the sabha.
But as he went to do the vastraharana of Draupadi, She remembered Krishna. Krishna immediately gave the Akshaya vastra to Her. As Dushasana was pulling Her garment, another garment was there on Her body. She didn’t rotate as shown in the serials. Like this, Dushasana pulled infinite sarees and finally fell. Here, why didn’t the Pandavas react? They did react, especially Bheemasena. Bheemasena criticizes Dharmaraja by asking Sahadeva to bring fire so that He could burn Dharmaraja’s hands for putting Draupadi on the stake. Arjuna then calms Him down. Bheemasena said to Arjuna, in his ear, “I told this because we must criticize the wrongdoing, and shouldn’t keep silent. I won’t do it literally.”
Duryodhana said, “Now, agree that everything happened due to Dharmaraja, then I will leave all of you!” and teased the Pandavas. At this, Bheemasena said, “My Dharmaraja is my elder brother and is always right. Plus, I am the elder brother to all of you. If you have guts, come on and fight me.” The Pandavas remained silent because of their respect for Dharmaraja. They were about to kill the Kauravas if they wanted, but Dharmaraja, with his eye coordination, asked them to sit down and not to say anything. But the question here is: why didn’t Krishna say anything about this? Why didn’t He stop Dharmaraja from going there?
To this, there is another strategic move by Krishna. SriMadhvacharya tells this in the Mahabharata Tatparya Nirnaya. He says that Krishna did this for a few reasons: 1. To expose the evil and deceitful nature of Duryodhana and the Kauravas to the whole world. Why was this necessary? 2. Because in the Mahayuddha that was to happen after 13 years, nobody should question why Krishna made everyone die by cheating. 3. He did let it happen because Dharmaraja did the Raajasuya Yagya, but He didn’t have the capacity to sustain all that much Punya himself. So, that punya was to be distributed among the Pandavas, with maximum Punya coming in Bheemasena and Draupadi’s account.
That’s why it was Bheemasena who actively criticized the act of disrobing Draupadi and rightly vowed to break Duryodhana’s thigh. SriMadhvacharya says that Duryodhana even asked Dharmaraja to put Krishna on the stake too. At this, Bheemasena vowed that He would kick Duryodhana’s face mercilessly for this, and it was completely rightly done by Bheemasena. Plus, all these people in the Dyuta Sabha, including Bhishma Pitamaha, Dronacharya, Krupacharya, Dhritarashtra’s Punya, should be transferred to the Pandavas, since they kept silent during this deceitful gambling game unfolding.
Another thing was to increase the sins of Duryodhana and the Kauravas, so that they could be killed outright. And what Krishna did in the Mahabharata yuddha was completely correct and just. So, this was all Krishna's plan. But they had to lose everything in the second round of gambling and go to the forest. Was this also Krishna’s plan? The answer is yes. This was also Krishna’s plan. The whole world runs on His plan; what is this? The reason was that Krishna had incarnated to reduce the burden of the earth.
Now, He had already killed the majority of demons like Pootana, Shakatasura, Trunavarta, Vatsasura, Bakasura, Dhenukasura, Arishthasura, Aghasura, Pralambasura, Keshi, Vyomasura, Kuvalayapeeda, Chaanura, Mushtika, Kamsa, and Kamsa's 11 brothers, Shankhachooda, the akshouhini army of Jarasandha 18 times, Kaalayavana, Shatadhanva, Shishupaala, Saalva, etc. But now, some demons were left, like Kirmeera, Jatasura, Krodhavasha raakshasas, Maniman, etc., who were living in the teertha kshetras and destroying their piety. So, He enabled the Pandavas too to contribute to His mission of reducing the burden of earth, thus serving Krishna.
NOW WHERE SHOULD THEY LOOK FOR ANY HELP?
For Satidevi, it was destined for Her to do dehatyaaga and be born as Aparna, and to remarry Mahadeva. For Sitadevi, She was already safe. But for the Pandavas, it was Krishna only who could help them in any way.
Thank you for reading, and bearing with me!😊🙏
Hope this helps!
Jay SriRam!
ShriKrishnarpanamastu!