AlaskanOilBaron, if Obama had been impeachable, Republicans would have impeached him.
They controlled both House and Senate during his presidency, and made clear from even before they won the House that they would try to impeach Obama. Some even cited birther conspiracies.
Whether or not you agree with Bush Jr or Obama on the military issues you mention does not determine whether these things are impeachable.
What Trump is accused of doing in Ukraine is very straightforwardly impeachable, viz the use of the power of his public office for his personal political gain. It was on a national security matter, not an attempt to get a good table at a restaurant, so is important for the country. It's also well-supported by evidence.
(Of course it would be nice to also have the additional evidence of the witnesses Trump has ordered not to testify – and why would he do that?)
There's a reason that Trump is being impeached now, when he wasn't on day one. That's because this specific abuse of power is now known about, it's well-defined, and it's impossible to ignore because of the precedent that would set.
Don't worry, though. Mitch McConnell has said that he (leader of the Republicans in the Senate) will make no attempt to give Trump a fair trial and will turn this into a purely political exercise, in which he will work for Trump.
And now that John McCain has died, there aren't many Republican senators likely to vote on the facts rather than play political games. So I'd say Trumpie is safe from actually being removed. You can rest easy.