Qantas is joining other international airlines in increasing airfares as the US-Israeli war in Iran drives up the cost of jet fuel.The airline announced that international fares will go up this week after the cost of jet fuel rose by up to 150 per cent in just a fortnight."Qantas International is increasing fares this week in response to rising costs including the significant increases in jet fuel prices," the airline said in a statement.READ MORE: Aussies could face $4400 fine