Kazys Škirpa, the incumbent chief of staff of the Lithuanian Armed Forces and a supporter of the farmer left wing coalition which ruled Lithuania at the time, was an opponent of the
1926 Lithuanian coup d'etat and tried resisting the takeover of the government by the consporators, however, his resistance to the military coup was started without any preparation and was largely post-factum, so Škirpa quickly swallowed the loss, gave up, accepted his removal from the position of Chief of Staff and instead became an attache to Berlin.
POD: Škirpa takes the rumors floating across Kaunas of a coup planned by Tautininkai-aligned officers more seriously and, with the pretext of ongoing army reform and relieving the old guard of the military, purges the main conspirators Ladyga and Plechavičius from the military. Škirpa's fight against a potential military coup, as well as their eroding popularity, alarm the Farmer-LSDP government of a possible coup and they roll back the worst of the excesses they went through to cut the funding of the military, regaining enough of the army's trust to prevent a coup attempt from firing regardless. Democracy in Lithuania is saved.
For now. Interwar Lithuania was far from a stable state and the Great Depression hasn't even happened yet, so it's likely that democracy in Lithuania is not going to last for too long regardless. However, even eight additional years would leave a lot of changes for the country. A longer experience with democracy would help solidify the country's democratic national identity and wouldn't give the Soviet Union a pretext to call Interwar Lithuania a ''fascist state".
More importantly, the comprehensive army reform which Kazys Škirpa started, which would have left the Lithuanian Army in a far stronger state than it was in OTL 1940, would not have been cancelled, which could have knock-on effects of its own.
Thoughts?