We are looking for a song (artist and title).
As figured out by both Lanny Strack and Rand al'Thor,
The image depicts five flags (American Samoa, Bolivia, Guatemala, Mozambique and Sri Lanka), with different types of weapons removed.
Combined with the title, the song must be
"Disarm" by The Smashing Pumpkins, which contains the line "disarm you with a smile".
Also, as noticed by Stiv,
The Smashing Pumpkins' logo is drawn in the four corners of Sri Lanka's flag.
As all of the weapons are removed from the flags (of American Samoa, Bolivia, Guatemala, Mozambique, and Sri Lanka) --- 'Knives Out' by Radiohead.
Another generic word meaning 'weapons' (of all types) more likely to be found in a song title is 'arms'. There are several songs which seem apt for the solution, including:
'Farewell to Arms', by Emerson, Lake, and Palmer
'Arms Out', by Curve
'Empty Arms', by Stevie Ray Vaughan
'Open Arms', by Journey
These flags are for
countries which have weapons in their national flags, but with the weapons removed.
So the song must be
Something about "without weapons" or "without guns and spears"? (I don't know many modern songs.)
Like Lanny Strack and Rand al'Thor already stated..
They are flags(American Samoa, Bolivia, Guatemala, Mozambique and Sri Lanka) with the weapons removed.
So, based on that...
I think the answer might be The Beatles - Happiness is a warm gun
You've written "with a smile" on the second part of the title, which makes me think of happiness. And also, to notice, these are all 'tropical' countries and this fits the warm part of the title of the song.