For what it's worth, in England, at least, the early 16th Century saw the
reign of Henry VIII.  Henry's adviser was Cardinal Wolsey, whose motto was
"Greatness through Peace". To this end he pioneered the "Balance of Power"
doctrine. To this end Henry married Catherine of Aragon, and the Spanish
alliance lasted until 1588.

Of course your period came a bit later. But if Tudor England was peaceful,
and the weather cold, it's a challenge for the thesis that cooling
brings warfare.

Mason Gaffney