There are severalSeveral factors that come into play here:
Element of surprise / reaction times. If whoever has the element of surprise is most likely to win a conflict, then yes, it would increase the frequency of warfare and conquest. Until reaction times to these sorts of assaults were improved, such that the element of surprise were lessened, this would remain the case. This is why the marines in the Aliens franchise use motion detectors: once the aliens get within visual range, they make quick work of marines. Similarly, it may be that your teleportation technology requires a large energy build-up in order to teleport any sizeable complexity or mass of troops. This may mean that it could be detected by opponents before it happens.
Cost. Finance is about managing risk; this includes financing wars. If the proposal looks good, the risk of being struck at first is high, and ethics are not in question, then a quick, first strike may be justified.
Level of paranoia. This again relates to the general level of ethics in the world (c.f. adherence to institutions like the Geneva Convention). If paranoia is high, then yes, it is highly likely that lethal first strikes would become commonplace.
Centralisation / deployment concentrations. If attacking capitals became commonplace, societies / nations would become more decentralised. It may also serve to decouple military administration further from civil administration. If an opponent aims for your heart, have more than one. This also leads to forces being deployed according to the risk factor inherent in not defending a particular facility.
If there were time to adapt societies to these tactics, you would end up with highly-compartmentalised, cell-based territories, probably consolidating resource gathering, manufacturing, residence, and military capabilities if not into the same cells, then into very tight localities of cells. This would make for nations that are most resistant to damage. Of course even this assumes no use of large area-of-effect weapons like nuclear weapons or excessive air power; if these are factored into the equation, then you would likely have scattered, self-sufficient compounds, or mutually-reliant compounds which would teleport supplies between them. Even in this case, it's likely that you'd end up with a hybrid approach -- scattered bunches of cells, such that every locale had compartmentalisation built in.
Then again if you consider the possibility of teleporting immediate-detonation nuclear weapons into enemy cells, you end up with armageddon in any case... a gross simplification is that whoever has the most cells, develops the necessary technology first and has the energy available to use it, wins. It's bedlam, because it's a case of hair-trigger timing if multiple nations gain the same technological capabilities around the same time.
More than anything else, could a technology be developed that could prevent teleport materialisation, even if only within a limited space? The high likelihood is that this would be the next arms race, just like Star-Wars-type programs were in late 70s and early 80s. Interception / interdiction would be the game changer.