It may not have been the definitive reason, but it sure helped as liberum veto seriously hampered any effective decision making, necessary when in a state of war.
What Sokrates forgot to mention, during the state of war the Sejm usually operated pod węzłem konfederacji, 'under the knot of confederation', literally. Which meant some privileges were suspended, including liberum veto.
The first european wide artillery book was by a Pole, the division system in military is a polish invention.
Husaria was the most efficient cavalry ever, Polish sabre the peak of development, and we had the best tacticians in Europe, by dozens.
Right. I meant the period of Rzeczpospolita Szlachecka, when the king could not wage a foreign war using the army of the state without the consent of Sejm, and didn't usually get it, as it meant increase in taxes. Can't recollect any aggressive war in this period, except for Batory's trip to Moscow.
The gentry youth's proficiency in arms came from the proud and sanctified Sarmatic Tradition, on one hand, but mostly from the constant turmoil in the East, which was not provoked by Poland, but offered military career opportunities for poorer gents, and for younger sons. I say 'mostly' because of Kochanowski and his references to the Sarmatic ideal of the time: grow corn and cattle in peace, and sell it for gold to hungry Englismen. And keep your karabela on you at all times.
Poland invaded Sweden, Poland invaded Russia, twice, Poland invaded Wallachia, Poland invaded the Teutonic Order, Poland invaded the electorate...
Russia, I know, Batory. Now count how many times Moscovites tried to invade Poland. In the diaries it comes back again and again like a broken record: 'and Moscow came again this year, got beaten by...' Sweden I do not remember, really. Wallachia, possibly, but with this unimportant nation I don't even remember when could it be. As for the Teutonic order and the Electorate, we are talking PLC here...
if you wanted to become a regional power in central, northern or eastern Europe you had to go through Poland to obtain it.
That would be Russia and Sweden. Turkey was mostly happy with what they got, and waged war on Poland as a means to stop the highly annoying Zaporozhan raids rather...
As for Poland being perceived as gutless? The German, Turkish and Swedish chronicles circa 1400s mid 1600s all repeat a comment that Poles cannot be beaten.
Yet they tried again and again, some of them. 'Gutless' as in 'not minding their business of conquering their weaker neighbours'. Who didn't always pay back with similar indifference.
if you're smack in the middle of Europe you will have to wage wars, loads of em.
Not quite so, I'd say. Mobilisations were usually late. West was having their own problems. South was the Jagiellonian House, and quite friendly. East... Tartars the eternal troublemakers, but Turkey as such not really interested, at the end of the day. Russians with their dream of power, yes, but you can't really call it a war every time. Sweden should have been dealt with better, both politically and militarily, if need be. During the 16th century Poland enjoyed peace, only later the demons woke up. As a result of neglecting the reasonable politics of the time, i.e. taking them out while they are weak. Hence - a pacifist nation.
The king was viewed as weak and for his part he wasnt really ready to run a huge powerfull state and he didnt really like or enjoy being the king in general and king of Poland in particular.
And don't forget the utterly stupid claim to the Swedish crown, which irked Gustavus in the first place.
You got it nicely in the nutshell, though, pleasure to read. Except that there would be no invaders, if PLC dealt with them in time, on its own terms, while in power. But that would be a different country then, wouldn't it. Different history with different twists