Small 'l' libertarians do not advocate initiation of force, but conservatives may.
A true conservative, while respecting constitutional restraints on federal power, might support initiation of force at the state or local level as their constitutions may allow. Or they might use the few enumerated federal powers that allow initiation of force, for example the power to declare war, to initiate force by starting offensive wars.
All true conservatives respect the Constitution and not some 'living' version. It's what they choose to do within it that distinguishes them from one another. And there is quite a bit of room for variation under the Constitution, and not everything constitutional is wise or proper.
Here's to strict constructionists whatever then call themselves [clink]. :<)