If you are talking about war, then no, that's not suicide. The aim is not to die, even though it might be likely.
Even suicide bombers don't have death as their primary aim - if they achieve the same result without dying, they would.
That depends on how you define "the same result". The assumed (in some cultures) moral superiority of the suicide bomber regardless of the legitimacy of the target can have considerable PR value. In a way that somewhat resembles a ponzi scheme, those at the very top may reap higher rewards, and so choose to elevate the tactic into a strategy.
More than one goal exists for each group, many of these goals are not mutually compatible, and different groups arrive at different mixes of tactics in pursuit of their goals and to resolve (or ignore) the various contradictions and incompatibilities in different ways, and these mixes change over time in reaction to a changing environment, including the S&T employed by other groups.
IOW, don't expect the strategies or tactics that groups use to settle on any sort of Nash equilibrium.
Even our culture has different interpretations for it - eg suicide vs sacrifice.
We morally condemn the former but elate the latter, even though the outcome is the same - a person dies.
Metaphysically, the meaning of suicide is given by the perceived meaning of death and the [lack of] belief in some sort of afterlife.
Is it a sin or not ? If there's an afterlife, will you be punished for committing suicide? What about the loved ones ? They will judge..
But for example, if you knew that this life is actually a realistic VR simulation that you've entered into, then suicide would be perceived as a sort of 'ESC' key - a way out of the simulation. Like exiting a game.
If a person's circumstance in life is such that the person is bound to suffer until death (eg. disease, mutilation or loss of everyone), then suicide might be looked at as a sort of release - a good thing.. There's the whole controversy regarding assisted suicide..
Then there's the sacrifice - going into battle screaming is a form of attempted suicide combined with attempted murder. At the end of the day, the battlefield participants are eventually split into killers and those who committed suicide. From this perspective, going to war is collective [attempted] suicide.
War is a form of temporarily suspending the moral rules we obey by (do not kill others or self) and people gladly participate in both killing others and themselves.
I guess my point is that tfa is looking at a very narrow spectrum of 'suicidal people' - suicide is a lot more prevalent than that and it's practiced not just by people with mental illness..