Tanks: I has it.
Leonid Brezhnev could have said this with a smile. For most of the Cold War, the Soviet Union and its Warsaw Pact allies had far more tanks in Europe -- and far more artillery, infantry, and conventional forces of any kind -- than NATO did.
NATO accepted this. Instead of trying to beat the Soviet Union by matching the size of its conventional forces, NATO invested in small, precise nuclear weapons. These could be used like artillery, launched against opposing armies during a battle. In the event of a US-USSR war, the Soviet Union's massive tank columns would simply be nuked instead of engaged in tank-to-tank combat. This strategy took advantage of NATO's better technology; the Soviets could not build such precise nuclear weapons.
The result was deterrence: the Soviet Union could not hope to conquer Western Europe, and so the Red Army simply sat.
But in the late 70's, things began to change. The Soviets introduced a new missile: the SS-20. This was a relatively small, accurate missile, with a nuclear warhead big enough to wipe out a military base. They took about 8 minutes to travel from the USSR to West Germany. In theory, they could be used to launch a sneak attack that would destroy NATO's bases in Western Europe (and thus destroy NATO's small nuclear weapons) and allow the Red Army to march to the Atlantic unopposed.
NATO responded by deploying a new nuclear missile in Western Europe: the Pershing II. This was a modified version of the older Pershing missile, which was already deployed, but it had a longer range and - importantly - was more accurate. Similarly, it could get from West Germany to the Soviet fatherland in under ten minutes.
The Pershing II spooked the Soviet Union: its accuracy meant that NATO could reliably nuke targets inside the USSR in a short amount of time (for comparison, an American ICBM would take about 30 minutes to get to Russia). This might allow NATO to destroy Soviet bases or even to launch a decapitation strike against the Kremlin.
All of these small, accurate missiles in Europe threatened to disrupt the relative peace of the Cold War. If both sides now believed they had a shot at pre-emptively neutralizing the other side's conventional forces, both sides might be tempted to start a European war.
Both sides realized this, and in 1987 Reagan and Gorbachev signed the Intermediate-Range Nuclear Forces Treaty, abbreviated the INF Treaty. This treaty banned intermediate-range nuclear missiles from Europe. As a result, the SS-20 and Pershing II missiles were removed and disassembled.
With this, the status quo ante returned. The USSR was safe from conventional attack by NATO because of its much larger army. NATO was safe from conventional attack by the USSR because it still retained its smaller tactical nuclear weapons.
As a side note: one of the consequences of the intermediate range nuclear missile crisis was me. My father, a defector from Communist Poland, was living in Germany in the 1980's. He was happy there and planned to stay. Then, one day, he saw a large protest against the Pershing II missile. One of the protesters was carrying a sign that said "Better Red than Dead". My father couldn't disagree more with this sign; it disgusted him so much that he moved to the United States, where he met my mother.