Without reading the other responses (so sorry if someone covered this idea already):
Technically, yes, technology can be separated in development, but in practice developments in one area tend to leak into others. Sometimes this is quite complex, but sometimes less so (like: the fact that they have transmitters that powerful indicates incredible power supplies, which can be applied to other technology, including some weapon designs, to devastating effect).
There's also the fact that, unless they are very long lived and very patient, traversing the stars requires one to get around those pesky laws of physics, most prominently the limitation of speed to that of light. If one can get around those (whether by some sort of star-trek "sub" space where the general limits don't apply or the mass modifying tech mass effect introduced, or something stranger), then one already has a vast body of science which lends itself well to developing tools for breaking stuff, quite possibly including us.
Although I can't help but think we're assuming too much about how alien life would look, react and need. They might be so foreign we just don't notice them as life, even if our detection equipment were up to the task of finding them.
Technically, yes, technology can be separated in development, but in practice developments in one area tend to leak into others. Sometimes this is quite complex, but sometimes less so (like: the fact that they have transmitters that powerful indicates incredible power supplies, which can be applied to other technology, including some weapon designs, to devastating effect).
There's also the fact that, unless they are very long lived and very patient, traversing the stars requires one to get around those pesky laws of physics, most prominently the limitation of speed to that of light. If one can get around those (whether by some sort of star-trek "sub" space where the general limits don't apply or the mass modifying tech mass effect introduced, or something stranger), then one already has a vast body of science which lends itself well to developing tools for breaking stuff, quite possibly including us.
Although I can't help but think we're assuming too much about how alien life would look, react and need. They might be so foreign we just don't notice them as life, even if our detection equipment were up to the task of finding them.