And while it seems reasonable to assume testosterone is a factor in aggression, I don't think most wars are started as quickly and as passionately as a fist fight.
But I do think it is worth tracking. When you look at the criminal world and how the acts of violence are so heavily weighted towards men, it does make one wonder.
Of course, the 20th century saw some changes, in the effectiveness and collaterality of weapons, and in the fact that some women do go to war. But basically, the later represents only a handicap to the armies allowing it. But as long as the war cannot degenerate into a wide scale (ie. involve the USA), or a nuclear war (ie. involve two countries with nuclear weapons), it's green light, and the same benefits can be expected.
Even about nuclear war, since we've developed small scale nuclear weapons (and since we can also see that the mid-to-long terms effect of nuclear bombs are rather benign, cf. Japan or Tchernobyl)), I would say that the probability to see a local and limited nuclear war is close to 1.
Business constraints (banking support, cost/benefit), risk and group morality play a far greater role in a countries decision than a single individuals gender.
So basically...no.
Russia was led into many wars by Catherine the Great.
Queen Victoria's reign witnessed most of the British Empire's colonial expansion.
...
So, no.
And look at the average interest of men and women. Games they play, movies they watch, not many men like to see Bridget Jones and not may women like to see Vietnam war movies :)
I would assume, on average, women start a lot less conflict. Non of these woman are at war as far as I know : http://www.pewresearch.org/fact-tank/2017/03/08/women-leader...