OK Trump, I'll try to explain to you what worries me in the Rules As Written (RAW), but keep in mind that english is a second langage to me.
All players draw back to 5 JUST LIKE THEY DO AT THE END OF ANY OTHER PLAYER'S TURN WHEN IT'S NOT THEIR TURN.
The thing is that the rules state that, after resolving an Instant Event card or a Siege conducted by a player, all player draw back to 5 cards. It doesn't mention anything about discarding the remaining cards in your hand (Step 3 of Player Turns) when you are not the "active player" (the player who plays during his own Player Turn). So it seems that Step 3 doesn't apply to you unless it's specifically your turn. Only Step 4 (draw up to five cards) applies to every player at the end of an Instant Event card or a Siege. Step 3 seems to be exclusive to the "active player".
"At the end of each player's turn and the Event phase, all players replenish their hand to five cards. Through card abilities, a player may draw additional cards. There is no maximum hand size." (Rules of Play, p.14)
See? Nothing is mentioned about discarding the remaining cards in your hand.
Now, why does it worry me? Let's pretend that you are Player 4 and that Player 1, during is own turn, chooses to attack you just for the fun of it. So be it, but you, Player 4, have only 4 Gold cards and 1 Forced March Tactic card in your hand. Since it's not your turn (it's Player 1's turn), you cannot play any of those card (because they cannot be played during a Siege). After taking damage tokens or loosing a Neutral City because of the Siege, according to RAW, you do not discard any of your remaining cards (which means all your cards in this specific situation), only Player 1 does (at the end or his turn, during Step 3). So, since you still have 5 cards in your hand at the end of the Siege (because you couldn't play any of them during the Siege), you cannot draw new cards either. It means that you're stuck with the same hand, and now it's Player 2's turn, and Player 2 knows that you couldn't defend yourself from the Siege conducted by Player 1. Knowing that your are probably defenseless, he choose to attack you (you know, just for the fun of it). Rince and repeat until it's your turn, if you're still alive at the beginning of your turn, of course.
Note that the exact same thing could happen to Player 1 after is own turn. Player 4 is not really at a disadvantage here. I just picked Player 4 as an example, because it was more easy to visualize. An Instant Event card, however, could be more harmful to Player 4 if it reveals that this player cannot defend himself against the Attack conducted by the Instant Event card.
This is my interpretation of the RAW, and it seems a little unfair. I don't know if this is really the rules as intended (RAI), so that's why I would like to know your thoughts about it. I hope I succeeded to make myself clear.