Regarding "Shell"

Number 2

(Because it is the only possible one)

Number 2 also.

Very interesting and worthwhile info about the supposed "wedding massacre" too.

I don't think #1 is an option.

I'd like to know the why.
How could you know al Sadr has not been defeated decisively?

Thank you all.

I can't think of any context where the verb shell implies defeating decisively. It certainly means to bombard in this context. It doesn't say anyting about the success of the bombardment.

The word "Shelled" can be used informally in baseball to refer to a pitcher who isn't doing very well. But this is a very specific idiom and doesn't apply here.

Thanks Ebrown_P, but my question was that without context what was your first reaction to the headline if your eyes touched it.
Yes, I wondered why could you figure out the word shell in "U.S. shells insurgency stronghold" just meant "to bombard", because we all know the US military forces are way stronger and modernized than the cleric militia. So in my view, I thought it was possible that the US troops has decisively defeated the cleric militia.

All its says, based on the words used is The US drops bombs on an pretty well-held fortification of people fighting the local power.

Sofia and the other respondents are right. 'Shell' never means to defeat decisively. Every native English speaker read that headline and understood immediately that it meant that US forces had used shells (artillery projectiles containing explosive charges) against a fortified position held by members of an insurgency.
It is possible that shelling can mean a decisive defeat - but you cannot assume that from this headline. If, for instance, the headline had read "US Shells Lemonade Stand", you could reasonably assume that the lemonade stand and any participants in the running of that stand were likely blown to smithereens. But what if this insurgency has many strongholds? And what if this particular stronghold is so strongly fortified that shelling would not destroy it?
So believe us when we say, 2.

Yes Eos. The most important thing is that I should know what is you native English speakers' first reaction to the word "shell".
Thanks.