I think you would be surprised by the answer Switzerland. Violations of their airspace were met with aggression and even capture of pilots and plane. /u/Georgy_K_Zhukov wrote a really interesting post on it. The portion directly related to your question can be found here. Search for the header [ At "War" ] to get right to the meat and potatoes of your question.

Part 1

I don't know if this fits exactly what you are envisioning here but let's talk about the Green Cadres and the Second World War in Yugoslavia.

But first some context:

The Kingdom of Yugoslavia before the Second World War was a state rive with difficulty. Ever since its inception at the end of World War I, one of or rather the major internal conflict revolved around how the state did or rather should reflect the nationalities in it. Mainly, it was about Serbia taking a rather dominant role while especially the political establishment of the Croatian part of the state felt that there should be stronger representation of Croatia and Croatian interests on the state (Slovenia subscribed to this too but they did and always had a bit of a special role, even in post WWII socialist Yugoslavia). This went as far as blocking parliamentary proceedings within the kingdom of Yugoslavia and the establishment of the dictatorship of King Alexander I in 1929. This was the same king later killed by the Ustasa and the radical Macedonian Revolutionary Organization in 1934 which lead to further tensions along political lines within Yugoslavia.

I'm mentioning this because it is important to know at least a bit of the back story for better understanding of the consequences of Nazi occupation. As foreign occupations are known to do, they in some cases tend to carry over internal conflicts in the occupied countries into armed struggle given the right circumstances. Such was the case Yugoslavia. The specific occupational policy in Yugoslavia needs to be understood in terms of German improvisation. The German attack on Yugoslavia and Greece and their occupation was not in as much planned as it was a military and political inconvenience for German leadership. Having planned the attack on the Soviet Union in 1941, Germany felt the need to militarily intervene in the Balkans because of the disastrous Italian invasion of Greece the same year and the officers' coup d'etat in Yugoslavia. Having long planned to militarily secure the southern flank of its attack on the USSR and to keep hold on the economic resources of Yugoslavia, Nazi Germany pressured it into the Axis. However, this was frowned upon by several political factions, especially in the Yugoslavian military, which was dominated by Serbs. And so, in March 1941, several high ranking officers initiated a coup d'etat with their new government announcing that it was not intending to honor the Axis agreement with Germany. This lead to the German invasion of April 41.

After a quick military victory over the Kingdom of Yugoslavia, the Third Reich faced the dilemma of how to organize occupation in a manner that was to spare them using much needed military resources. This lead to the creation of the Independent State of Croatia (NDH) under the Ustasa, which itself was more of an improvised solution since the most Croatian party with the most support refused collaboration with the Nazis and the Ustasa was by far not a party supported by the masses but rather a conspiratorial revolutionary organization.

So while Croatia became a satellite state with a rather dubious collaborationist regime, Bosnia was incorporated into Croatia, Slovenia annexed by the Third Reich, and what was called "rump Serbia" placed under the administration of the Wehrmacht (the latter due to Hitler's hatred of the Serbs, him being an Austrian). To make things even more complicated, large swaths of territory of former Yugoslavia was placed under Italian occupation seeing as to how Mussolini claimed the Mediterranean as his domain. But the important story for the purpose of this post concerns the NDH, the Ustasha and the Bosnian Muslims.

The Ustasha has been described by historian Alexander Korb as the radical product of the disintegration of the Habsburg empire. Racialist nationalists, they were a conspiratorial terrorist organization that had fought the Yugoslav state and the Serbs in particular. When they took over in Croatia and subsequently founded the Independent State of Croatia (Nezavisna Država Hrvatska, NDH) they were in essence the second choice of the invading Nazi regime because the conservative Agrarian party had refused to collaborate. The Ustasha, at the time of their takeover a group of about 3000 people, quickly set to put their policies against Jews, Roma, and Serbs into bloody practice. They for example dislocated about a third of the Serb population of Croatia, while another third was to be killed, and the final third to be converted to Catholicism.

Now, where do the Bosnian Muslims figure into this. This is where it gets a bit complicated. The Ustasha wanted to use the Muslims as pawns in their policy of forced expulsion, murder and forced conversion against the Serbs. They declared that the Bosnian Muslims, which they initially regarded as »Muslim Serbs« to be Croats and started spreading hatred between the Serbs and the Muslims in Croatia, in part by drafting Muslims into their security forces, in part by adopting Muslim symbolism such as the Fez. This tactic worked to a certain extent, and the Serbian nationalist resistance in Croatia and Serbia, the Chetniks, started not only attacking the Germans and Ustasha but also Muslim communities.

At the same time, a considerable number of Bosnian Muslims were also targeted for imprisonment and to be killed by the Ustasha because they were so-called »gypsies«. Roma in Croatia had often adopted the Muslim faith and either settled down or continued their Roma lifestyle. Since the Ustasha targeted so-called gypsies as part of their policies of racialist cleansing, the did indeed imprison and often kill in a very brutal and gruel way, considerable amounts of Muslims.

Basically, a lot of Bosnian Muslims were caught between being victimized by the Chetniks because they believed them to be Ustasha and the Ustasha for they believed them to be so-called gypsies. This motivated quite a few of them to join the Partisans, who had a policy of being open to all nationalities (in 1941 e.g. people from Bosnia and Herzegovina were the third largest group in the Partisan movement after Serbia proper and Montenegro, by 1945 about a 100.000 of them fought with the Partisans). But this open was also not necessarily open to all since the Partisans, being communists, were not exactly regarded highly withing faithful communities.

This problem of being caught between the fronts was compounded further by the lack of central leadership within the Bosnian Muslim community. Bosnian Muslims had not been a nationality within Yugoslavia before the war, like it became later under Tito. The only thing resembling something of a political institution (aside from those who fought with the Partisans) was the clergy. And in this group reactions varied.

On October 12 1941, 108 notable Muslim citizens of Sarajevo declared their opposition towards the Ustasha policy towards Serbs. This came in part from them feeling like they were caught between the fronts, partly because of their horror towards the brutal treatments of Serbs by the Ustasha. In this resolution, they condemned the cruelty of the regime and highlighted the persecution of many of their own. Soon, similar resolutions followed from other Muslim communities. Of course, this didn't really bring about the desired effects and the signatories were subsequently threatened with imprisonment in a Concentration Camp by the Ustasha. This lead to a variety of responses.

Those who were liberal or inclined towards the left began seeking their salvation with the Partisans but those who were opposed to communism on grounds of their religion did not seek that option. Instead, in December 1941, they went on to found the Green Cadres (Zeleni kadar), a privately organized Bosniak Muslim paramilitary.

It also gets a bit complicated here: "Green Cadres" is both the name for the Muslim paramilitary in Bosnia during WWII as well as for another phenomenon, namely bands of Croatian deserters from the Austro-Hungarian Army during World War I who refused to support the Austro-Hungarians and roamed the country side of Croatia and Bosnia in 1917 and 1918 as outlaws with a military organization.

Anyways, the Bosnian Green Cadres came into existence in December 1941 when the Italian occupation in Croatia struck a deal with the local Chetniks to hand over control of the city of Foča to them. The Italians, as the Germans, were spread thin and didn't want to fight Partisans and Chetniks at the same time, all the while the Chetniks grew in size due to the anti-Serb policy of the Ustasha. Because the Bosnian Muslims of the region feared the Chetnik take-over, they started organizing into self-defense militias in order to protect their people from Chetnik ire. They couldn't prevent a massacre from occurring but this instilled in many Muslims the necessity for such self-defense forces on a broader scale.

While in the following months, Green Cadres were organized sporadically and without any central organization, it was in August 1942 when Bosniak leaders at a conference in Sarajevo founded the People's Committee of the National Salvation of Bosniaks, which included the Green Cadres in its military. The main mission of the Green Cadres was the protection of Bosniak populated areas in Bosnia and to control the movement of the Orthodox population in the area.