Nördlingen wasn’t quite a knockout punch for the Swedes, but the Protestant cause was near complete collapse. Aside from a fractured remnant of the Heilbronn League, Johan Baner’s Swedish army of 23,000 abruptly mutinied. Reduced by the war and disease, just 10 percent of the army was Swedish or Finnish. The vast majority of the remaining mercenaries had little love or loyalty for their paymasters; even that word was generous given how late and infrequently the Swedes had the funding to pay for their army. Cut off in the ruins of Magdeburg by the grumbling mutineers, Oxenstierna was paralyzed. As the Swedes struggled to regroup one of their last major holdings in the south, the city of Augsburg, came under siege. Over the winter of 1634-35, the city’s town council and the Swedish garrison took increasingly brutal steps to hold out. The “useless poor” were expelled from the city first. Buildings were broken down for firewood, leaving more of the lower class to freeze in the cold. Reports of cannibalism were not unheard of. By March after a horrific six month siege the Swedish garrison marched out under a negotiated settlement. A loss, for the city of Augsburg more than anyone else. By one estimate, the siege reduced the city’s population from 70,000 to 16,000.
From home reports piled on the misery for Sweden. The Polish were making some ominous moves towards the Swedish foothold on the southern Baltic. Christian IV, still King of Denmark, had made a discreet side alliance with the Hapsburgs, and his agents were among the provocateurs pushing Baner’s army towards desertion and insurrection. At any time one or both of them could knife Sweden in the back. The situation was calamity on all sides, and Oxenstierna lamented that, “we pour our blood here for the sake of reputation, and have naught but ingratitude to expect”. In light of Augsburg, perhaps the Swedish Minister could have pondered whose blood was actually being shed in this campaign.
The Emperor and his son had done all they could to encourage the Swedish collapse, and they were consolidating their power for the final mopping up. The added benefit of the Peace of Prague was that it had not just applied to Protestants like Saxony or Brandenburg, but rather to all German signatories. Maximilian and his Catholic League were now marching formally under the Hapsburg Eagle. There would be no more side deals with the French, no more evasive back biting or undermining from the Bavarian weasel. To assuage their ally’s wounded pride, Ferdinand III offered his sister in marriage to Maximilian as his second wife.
With Sweden on the ropes, the last remaining Protestant force still in play were the United Provinces. The Dutch were having a hard time of the war as it stood, even the Spanish under the Cardinal-Infante Ferdinand were experiencing a brief resurgence. The rebellious Flemish in Belgium had knuckled under, and the Cardinal-Infante was busily reversing the recent gains the Dutch had made. After 70 years of fighting the Dutch peace party was large enough that if the right deal came along, even if it was unfavorable, they might overrule the House of Orange and leap it instead of fight on.
The only chance for both the Netherlands and Sweden was for their shadowy benefactor Richelieu to finally make an open move, and the Cardinal shared the feeling. Richelieu may have been a gambler with events, but his game was poker, not roulette. He liked being able to assess his opponents and his chances, and always trusted a safer bet to the riskier ones. It was the kind of decision making that had led him to make an alliance with the Swedes in 1631, offering cash for their army in exchange for a promise that Sweden would seek French approval before ending their little intervention in the Holy Roman Empire. It allowed the French to tie up their enemies and spend time focusing on other matters. Likewise generations of French diplomats had known the Dutch were hemorrhoids on the Spanish empire, and did everything they could to make the rebellious Dutch as painful as possible for Madrid. Most recently Richelieu had even agreed to send the Dutch a French army that technically would serve under their banner. Yet for all of their meddling, outright war posed another danger entirely.
Almost the entirety of France’s national borders were potentially exposed to the Hapsburgs, who would have the luxury of picking their invasion route and deploying armies that had been busy fighting the rest of Europe for decades now. Against this, France had an army of 50,000 men to guard the entire border and essentially no experienced military leaders. There were plenty of nobles who called themselves “officers”, but even the King considered them little more than militant peacocks. Military rank equated to the number of men the officer had corralled into service and the titles behind their name, rather than any particular aptitude for war.
As a result, the only two of any consequence France could employ was a former leader from the Huguenots, and the morally flexible Bernhard of Saxe-Weimar. Still leading the remains of the Protestant army near the Rhine, Bernhard had happily agreed to switch his immediate loyalty in exchange for control of Alsace. As for the army these unlikely characters would lead, that was in an even more sorry state. Even conservative estimates suggested Richelieu and Louis XIII would have to double their army if they wanted to stand a chance. As for paying for this escalation, in this area as well the French were nowhere near as secure as they pretended. While the Cardinal had periodically attempted to increase revenues and reduce the provincial corruption that sapped taxes, at the end of the day much of the shortfall was being covered by loans from the banking sector. Foreshadowing the fall of the French monarchy, Richelieu was already in the habit of hiding thirty percent or more of the state budget on a separate set of books to conceal both how much was being borrowed and the extortionate rates involved.
As a result, Richelieu’s advisers noted with hilarious understatement that “by increasing his Majesty’s forces, which are already very large, it will become difficult for him to pay them all on time”. Their suggested solution to the fiscal grief was to encourage the soldiers to “live off the land”. The same land in fact, that soldiers had been treating this way for almost two decades now. If ever there was an example of a tragedy of the commons, it was the most fiercely contested pieces of Germany.
In the end, the French intervened for almost stereotypically French reasons. In 1631 with the Swedish bearing down on him, the Catholic Elector of Trier had made like Bavaria and appealed to the French to rein in their attack dogs. While the plea had been no more effective than it had been for Maximilian, technically the Elector was under French protection. As the tides of war shifted the Spanish decided to make an example of the Elector of Trier and carried him off in a raid in 1635. It was a flimsy cassus belli, but it would do. On May 21st, 1635, France formally declared war on Spain. By August 1636, this was formally expanded with a declaration of war on the Holy Roman Empire. The final death spiral of the war had begun.
 Twamley, Z. (2014). When Diplomacy Fails: The Thirty Years War.
 Given that the new Archduchess was A) 37 years younger than Max and B) his niece by marriage, the match was a surprisingly affectionate one.
 Though meddling by the Madrid home government would be one of many pains in the Cardinal’s side for the rest of his life.
 King Charles of England had, of course, by this point dug himself so deeply into a hole of self-rule and piggish imposition that no amount of shouting for aide from the Dutch could reach him
 National sovereignty was a much more nebulous concept pre-Westphalia.
 Wilson 2009