1. Did Germany just run out of troops at the end?
Well....from the beginning to the end....Germany had mobilized about 13.2 million men over the war, with around 2 million dead and millions wounded or captured by 1918.
Conscription had caused problems in the the population (especially younger and less fit men), but Germany still had reserves.
The real issue was the inability to supply, equip, and sustain these forces, coupled with collapsing morale and political will (particularly the SPD Party).
2. Was the end a surrender or a armistice?
Germany sought an armistice based on U.S. President Wilson’s Fourteen Points, hoping for lenient terms.
The armistice gained.....simply halted fighting, but Germany’s army was never fully defeated on the battlefield, leading to the “stab-in-the-back” myth later exploited by nationalists.
3. Was the spring 1918 German offensive a big deal?
On paper....this March-July period was aimed to break Allied lines before American troops fully arrived.
What you can say....there were some brief initial gains, then the offensive stalled due to overextended supply lines, heavy casualties (Germany lost about 700,000 men in 1918 alone), and effective Allied counterattacks, notably the Hundred Days Offensive (August-November 1918).
Germany’s army were somewhat depleted....mostly due to poorly trained replacements (the conscripts of the fall of 1917).
I need to add this final note.....war weariness (summer of 1918) had sparked unrest. The Kiel Mutiny (October 1918) by German sailors spread into the November Revolution, with workers’ and soldiers’ councils demanding peace and political reform.
All of this added up to the Kaiser’s abdication on 9 November 1918, which signaled the collapse of the German monarchy, pushing the new government (led by the SPD) to seek peace.
Had the spring offensive been effective....had the Kiel mutiny not occurred with the revolutionary business...had the monarchy not have collapsed, then the war would have likely gone into 1919 (for another year).