What Is Jihad----According to Quran

I would like to know  views of members on Jihad.

What is Jihad.Under which circumstances is it obligatory for a Muslim/an Islamic country to declare Jihad.When an Islamic nation declares Jihad on a non-islamic nation is it obligatory for that nation to make a formal proclaimation of Jihad.Is Jihad just war or there are different kinds of Jihad {including peaceful ones}.Who has the authority to declare Jihad and on whom.What is the punishment if it is found out that the reasons for which Jihad was made werent valid ones.

What does the Quran say regarding Jihad.

It is obligatory for the head of the state (or the Khalifa of Muslims) to formally declare a Jihad (resistance) against aggression.   Like Azimuth has mentioned, the head of the state is the one responsible for taking such a decision. 

When the declaration is made, it becomes obligatory (fardh kifaya = collective duty) upon all capable males to participate in the defence of their faith and lands.  If the head of the state, however, determines that the manpower is insufficient, it becomes obligatory (fardh 'ayn = indivudual duty) upon all Muslims; male, female, old and young, to participate in the defence.

It is very unlikely that a declaration of struggle (Jihad) could turn out to be baseless.

According to the Qur'anic verse, "Fight in the cause of Allah those who fight you, but do not do aggression, for Allah loves not the aggressors. Fight in the way of Allah against those who fight against you, but begin not hostilities. Lo! Allah loveth not aggressors." [2:190-192]

 ' The ink of the scholar is more holy than the blood of the martyr'       Prophet Muhammed (PBUH).

Jihad is simply a self defence if the islam in dngrerous then the Jihad must declear.

NO need to explain cause Azimuth covered it briefly.

thanks brother.

So, why there is no religious declaration from the heads of the state (or the Khalifa of Muslims) against suicide bomber and taker of hostages?

There is not a Khalifa and, It was declared a lot of time.

 And why and with power Osama bin Laden claims Jihad and who are the followers of him? 

You can also claim jihat, but you need some follower like laden  have fanatics.

Suicide is not permitted at islam, but  this is not only one sin of theirs. They even wont respect war laws of islam. Never attack temple of other religious building.(they did this in Turkey), never attack innocents, and civilians.(Of course at wars, some  civilians die, but they deliberately choose civilians as targets.)

Thanks, I can't claim Jihad because I'm not a muslim.

You can is it a justified claim or not is another question, but this question is also valid of ladin  too.

What I don't understand is why there are so many people, young people, following Osama and how they become fanatics, which are the reasons?

Israel-Palestine conficts(israil cruelty is not less than ladin, and USA  is supporter of israel), low education, sufference under bad ruling, fanatism.

USA have  only one of these fanatics, and remember what they did in Iraq.(Sure they dont represent USA, but ladin also dont represent muslims)

And there are not so  many young people.number of followers of Usame are not much.

briefly Osama bin Laden said that the reasons for Islamic Nations such as Palistine misery and weekness are the West and the USA in particular for supporting Israel and interfering with Muslims affairs. so he is saying that since the Western word claiming that they are Democratic then Each civilian of these governments participated in the misery of the Palistinians and other muslims around the world, and hold responsible for the Actions of their governmnets.

from that Osama justify his Civilian targeting.